Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Redox-active polymers have garnered significant attention as promising materials for redox capacitors, which are energy-storage devices that rely on reversible redox reactions to store and deliver electrical energy. Our focus was on optimizing the electrochemical performance in the design and synthesis of redox-active polymer electrodes. In this study, a redox-active polymer was prepared through step-by-step synthesis on a gold electrode. To achieve this, we designed an automatic sequential polymerization equipment that minimizes human intervention and enables a stepwise polymerization reaction. The electrochemical properties of the polymer gold electrodes were investigated. The degree of polymerization of the polymer grown on the gold electrode can be controlled by adjusting the cycle of the sequential operation. As the number of cycles increases, the amount of accumulated charge increases proportionally, indicating the potential for enhanced electrochemical performance.

DOI： 10.3390/polym15173517

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Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Bandgap and energy levels are crucial for developing new electronic and photonic devices because photoabsorption is highly dependent on the bandgap. Moreover, the transfer of electrons and holes between different materials depends on their respective bandgaps and energy levels. In this study, we demonstrate the preparation of a series of water-soluble discontinuously π-conjugated polymers through the addition–condensation polymerization of pyrrole (Pyr), 1,2,3-trihydroxybenzene (THB) or 2,6-dihydroxytoluene (DHT), and aldehydes, including benzaldehyde-2-sulfonic acid sodium salt (BS) and 2,4,6-trihydroxybenzaldehyde (THBA). To control the energy levels of the polymers, varying amounts of phenols (THB or DHT) were introduced to alter the electronic properties of the polymer structure. The introduction of THB or DHT into the main chain results in discontinuous conjugation and enables the control of both the energy level and bandgap. Chemical modification (acetoxylation of phenols) of the polymers was employed to further tune the energy levels. The optical and electrochemical properties of the polymers were also investigated. The bandgaps of the polymers were controlled in the range of 0.5–1.95 eV, and their energy levels could also be effectively tuned.

DOI： 10.3390/polym15122738

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DOI： 10.3390/polym14122472

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Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Society of Polymer Science, Japan  

DOI： 10.1295/koron.2018-0043

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Language：English  

Bovine serum albumin (BSA)-capped gold nanoclusters (BSA-Au NCs) are attractive photosensitizers for efficient singlet oxygen 1O2 generation owing to their high-water solubility, low toxicity, and the broad absorption from UV to visible wavelengths, and the long lifetime of the electronic excitations (of the order of microseconds). However, the 1O2 generation efficiency of BSA-Au NCs is relatively low. In the present study, a conjugate of BSA-Au NCs and methylene blue (MB) (BSA-Au NC-MB conjugate) has been developed to improve 1O2 generation for antimicrobial photodynamic therapy (aPDT). The BSA-Au NC-MB conjugate demonstrated enhanced 1O2 generation compared to the case of BSA-Au NCs and effective aPDT ability under white-light LED illumination for only 1min due to the resonance energy transfer from the Au NCs to the MB in the conjugate. To the best of my knowledge, this is first report of Au NCs on the resonance energy transfer application for efficient 1O2 generation. Therefore, the BSA-Au NC-MB conjugate is a novel photosensitizer for 1O2 generation that shows great potential for aPDT, and the present study also develops a very simple strategy to fabricate albumin-based nanoparticles for PDT.

DOI： 10.1016/j.jcis.2017.09.011

PubMed

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Here we report on the induction of orientation of rod-like semiconducting molecules by depositing them on the surface of conjugated polymers thin films prepared by friction transfer method. We also discuss about induction of orientation of multilayers and mixed films of p-type and n-type semiconducting molecules. It was found that when pentacene thin films were deposited on the friction-transferred films of polythiophene, the long axis of pentacene was oriented in parallel to the polythiophene backbone direction. Photo-electric conversion devices prepared with the oriented pentacene films showed higher conversion efficiency than those prepared with pentacene whose orientation was not controlled. For p/n strucures, we prepared 2 types films of α-sexithiophene and perfluoro-sexithiophene sequentially deposited and co-deposited on the friction-transferred polythiophene films, and both structures showed good orientations.

CiNii Books

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society  

A plasmonic dish was fabricated as a novel cellculture dish for in situ sensitive imaging applications, in which the cover glass of a glass-bottomed dish was replaced by a grating substrate coated with a film of silver. Neuronal cells were successfully cultured over a period of more than 2 weeks in the plasmonic dish. The fluorescence images of their cells including dendrites were simply observed in situ using a conventional fluorescence microscope. The fluorescence from neuronal cells growing along the dish surface was enhanced using the surface plasmon resonance field. Under an epi-fluorescence microscope and employing a donut-type pinhole, the fluorescence intensity of the neuron dendrites was found to be enhanced efficiently by an order of magnitude compared with that using a conventional glass-bottomed dish. In a transmitted-light fluorescence microscope, the surface-selective fluorescence image of a fine dendrite growing along the dish surface was observed
therefore, the spatial resolution was improved compared with the epi-fluorescence image of the identical dendrite. (Chemical Equation Presented).

DOI： 10.1021/am505579u

Scopus

PubMed

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Benzylidene polyester was successfully synthesized and highly intense fluorescence of a Cu2+ benzylidene complex was observed. The reason for the significantly enhanced fluorescence "turn on" was elucidated for efficient and effective detection of Cu2+ ion.

DOI： 10.1246/cl.140239

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Control of the molecular orientation of regioregular poly(3-alkylthiophene)s (RR-P3ATs) improves the performance of field-effect transistors and organic photovoltaic devices (OPVs). However, most thiophene ring planes of the RR-P3AT molecules (except RR-poly(3-butylthiophene)) in films formed by the conventional spin-coating method stand on the substrate, that is, edge-on orientation. Orientation control of RR-poly(3-dodecylthiophene) (RR-P3DDT) molecules in films formed by the friction transfer method is reported and the performance of OPVs based on friction-transferred RR-P3DDT films is compared to that of OPVs based on spin-coated films. The films are investigated by polarized ultraviolet-visible light absorption spectroscopy, Fourier transform infrared spectroscopy, and grazing-incidence X-ray diffraction measurement. For friction-transferred films, the RR-P3DDT molecular chain is uniaxially aligned parallel to the substrate plane. In addition, the thiophene ring planes of the RR-P3DDT molecules are also oriented parallel to the substrate plane, that is, face-on orientation. The power conversion efficiency (PCE) and fill factor of the RR-P3DDT/C-60 bilayer OPVs based on the friction-transferred RR-P3DDT films are higher than those of devices based on spin-coated films. The PCE and photocurrent of the device based on the friction-transferred film are larger under irradiation with polarized light parallel to the RR-P3DDT molecular chain direction than with polarized light orthogonal to the chain direction. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40136.

DOI： 10.1002/app.40136

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

White polarized light emitting devices are produced by combining oriented beta-phase polyfluorene (PFO) films with alpha-sexithiophene (6T) on top. Highly oriented PFO films are fabricated with the friction transfer method and exposed to toluene to partially change their conformation to the metastable beta-phase PFO without loss of orientation. Orange emitting 6T is then deposited by the conventional vacuum deposition method on top of the blue emitting oriented PFO films. We studied the effects of 6T thickness on the emission color and the results indicated that whitening is possible by depositing 6T at a thickness of 1.5 nm on beta-phase PFO. High polarization of both PFO and 6T emitting regions in the electroluminescence spectra suggested that 6T molecules are oriented parallel to the PFO molecules. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.01AC01

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

We have been studying oriented thin films of polymers fabricated by the friction transfer method, which allows a variety of conjugated polymers to be aligned into highly oriented films. However, with this method it is difficult to prepare oriented films from a mixture. In this work we prepared oriented thin films of a mixture of regioregular poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM), which is a promising combination for application in organic solar cells. We obtained oriented blend films of P3HT and PCBM by the friction transfer method from a solid block prepared from a mixed solution with a weight ratio of 1 : 1. Atomic force microscopy shows that microscale phase separation took place in the blend films. Polarized UV-visible spectra show that the P3HT chains were aligned parallel to the friction direction in the blend films. X-ray diffraction studies suggested that the preferred orientation of P3HT crystallites was the "face-on" orientation in the blend film. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.01AB05

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Language：Japanese   Publisher：The Materials Research Society of Japan  

Brain-derived neurotrophic factor (BDNF) has been studied for one of candidate proteins for brain disorder. Its detection has been performed with Enzyme-Linked Immunosorbent Assay (ELISA) at present. However, developments of more rapid BDNF detection system using a small amount blood sample has been demanded and it is important to find the anti-BDNF antibody with highly affinity. In this study, BDNF was rapidly detected with the enhanced fluorescence in the sandwich assay prepared on the Ag/ZnO-coated plasmonic chip. We used protein-protein interaction among two peptides constituting BDNF, Mature-BDNF and Prodomain-BDNF, for detecting Mature-BDNF. As for the capture part, Prodomain-BDNF linked with anti-ZnO antibody was immobilized to the ZnO surface of a plasmonic chip. As the detection part, primary antibody (monoclonal or polyclonal antibody) and secondary labeled IgG antibody were used. The detailed analysis of the primary antibody provided the important information on the BDNF detection. Compared with large nonspecific adsorption between Prodomain-BDNF and primary polyclonal antibody, monoclonal antibody was found to show the specific affinity with Mature-BDNF. Mature-BDNF was quantitatively detected with the monoclonal antibody on the plasmonic chip until the concentration lower than that detectable on the glass slide.

DOI： 10.14723/tmrsj.39.361

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

Plasmonic chips, which are grating replicas coated with thin metal layers and overlayers such as ZnO, were applied in immunosensors to improve their detection sensitivity. Fluorescence from labeled antibodies bound to plasmonic chips can be enhanced on the basis of a grating-coupled surface plasmon resonance (GC-SPR) field. In this study, as one of the representative candidate protein markers for brain disorders, the brain-derived neurotrophic factor (BDNF) was quantitatively measured by sandwich assay on a plasmonic chip and detected on our plasmonic chip in the concentration of 5-7 ng/mL within 40 min. Furthermore, BDNF was detected in the blood sera from three types of mice: wild-type mice and two types of mutant mice. This technique is promising as a new clinical diagnosis tool for brain disorders based on scientific evidence such as blood test results. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.06GK01

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Management of alpha-sexithiophene (6T) molecular orientation is a key issue to improve the performance of organic photovoltaic (OPV) devices based on 6T thin films, which act as p-type semiconductor layers; however, it is difficult to produce 6T layers with the molecules lying on smooth surfaces, including oxide covered substrates. We have succeeded in orienting the 6T molecules on oriented conductive polythiophene (PT) films, parallel to the oriented PT molecular axis; i.e. parallel to the substrate, by evaporating 6T in vacuum. Here, we reported planar heterojunction (PHJ) OPV devices consisting of 6T films with molecular orientation parallel to the substrate. The orientation of 6T led to improvement of the power conversion efficiency (PCE) in these PHJ OPVs. The average PCE of PHJ OPVs with oriented PT was 2.8 times higher than that without PT. The PCE and the maximum value of the short-circuit photocurrent action spectra of the OPV with the PT was larger under irradiation of polarized light parallel to the 6T molecular axis than that orthogonal to the axis. On the other hand, the PCE and the action spectra of the OPV without the PT did not show the response to polarized light. (C) 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.orgel.2012.09.017

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

DOI： 10.1002/pola.26053

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

A plasmonic chip with a periodic structure coated with thin metal films was fabricated and applied to bioimaging under a fluorescence microscope. By using the enhanced electric field of surface plasmon resonance excited on the chip, an enhanced fluorescence of samples was observed by conventional fluorescence microscopy. In this study, neurons were cultured on a plasmonic chip, which was used instead of a glass-bottomed dish or cover glass; the received fluorescence images of neuron dendrites were more than four times brighter than those obtained from similar specimens cultured on a glass-bottomed dish and observed using an upright fluorescence microscope. (C) 2012 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.51.06FK10

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

As an extension of our continuing studies concerned with the mechanistic discussion of network formation in the free-radical crosslinking (co)polymerization of multivinyl monomers, this work refers to the skewered reactions in the crosslinking (co)polymerizations of liquid polybutadiene rubber (LBR) as an internal olefinic multivinyl monomer or crosslinker, especially focused on the competitive occurrence of both addition or skewered reaction to internal carboncarbon (CC) double bonds and abstraction reaction of allylic hydrogens in LBR by growing polymer radical. Thus, LBR is regarded as an internal olefinic multiallyl monomer-linked allyl groups (?CH?CH?CH2?) with methylene units (?CH2?). First, gelation in the polymerization of LBR was explored in detail, especially at elevated temperatures. The occurrence of intermolecular crosslinking was easier in the order LBR > LBR containing 20 mol % of 1,2-structural units > liquid polyisoprene rubber. Then, we pursued the polymerization of LBR using dicumyl peroxide (DCPO) as typical organic peroxide used at elevated temperatures. The primary cumyloxy radical generated by the thermal decomposition of DCPO may add to CC double bond or abstract allylic hydrogen or undergo beta-scission to generate a secondary methyl radical. The initiation by the cumyloxy radical was omitted. The ratio of allylic hydrogen abstraction to beta-scission reaction was estimated; thus, only 39% of cumyloxy radical was used for the allylic hydrogen abstraction reaction. The addition of methyl radical to CC double bond was clearly observed. Finally, we pursued the intermolecular and intramolecular skewered reactions in free-radical crosslinking LBR/vinyl pivalate copolymerizations. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

DOI： 10.1002/pola.25858

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Our previous mechanistic discussion of network formation in chainwise crosslinking multiallyl polymerization was extended to stepwise crosslinking diepoxide/diamine polymerization, typically including bisphenol-A diglycidyl ether (BADGE) and 4,4'-diaminodiphenylmethane (DDM). In allyl polymerization a monomer chain transfer is an essential termination reaction, providing only oligomeric primary polymer chains. Therefore, crosslinking multiallyl polymerization could be in the category of a classical gelation theory. Thus, the gelation behavior was discussed by comparing the actual gel point with the theoretical one. Then the resulting network polymer precursors (NPPs) were characterized by size-exclusion chromatography-multiangle laser light scattering-viscometry to clarify the stepwise crosslinking BADGE/DDM polymerization mechanism. Notably, the intrinsic viscosity ratio [eta](NPP)/[eta](Linear) tended to decrease with the progress of crosslinking and finally, it reached less than 0.2. This suggests that the structure of resulting NPP becomes dendritic at a conversion close to the gel point. These dendritic NPPs can collide with each other to form crosslinks between NPPs, eventually leading to gelation as a reflection of the high concentration of NPP. The dilution effect on gelation was marked in polar solvent; no gelation was observed at a dilution of 1/5. However, in nonpolar solvent the gelation was promoted by dilution; this is ascribed to enhanced crosslink formation between NPPs through hydrogen bonding due to abundant hydroxyl groups in the NPP generated by the polyaddition reaction. Finally, the subject of "Is cured epoxy resin inhomogeneous?" is briefly discussed. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 3997-4004, 2011

DOI： 10.1002/pola.24841

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

DOI： 10.1021/ma1029423

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL PUBLISHING, INC  

For a deeper understanding of allyl polymerization mechanism, the reinitiation efficiency of resonance-stabilized monomeric allyl radical was pursued because in allyl polymerization it is commonly conceived that the monomeric allyl radical generated via the allylic hydrogen abstraction of growing polymer radical from monomer, i.e., "degradative monomer chain transfer," has much less tendency to initiate a new polymer chain and, therefore, this monomer chain transfer is essentially a termination reaction. Based on the renewed allyl polymerization mechanism in our preceding article, the monomer chain transfer constant in the polymerization of allyl benzoate was estimated to be 2.7 x 10(-2) at 80 degrees C under the polymerization condition, where the coupling termination reaction of growing polymer radical with allyl radical was negligible and, concurrently, the reinitiation reaction of allyl radical was enhanced significantly. The reinitiation efficiencies of monomeric allyl radical were pursued by the dead-end polymerizations of allyl benzoate at 80, 105, and 130 degrees C using a small amount of initiators; they increased remarkably with raised temperature. Thus, the enhanced reinitiation reactivity of allyl radical at an elevated temperature could bias the well-known degradative monomer chain transfer characteristic of allyl polymerization toward the chain transfer in common vinyl polymerization. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 156-163, 2011

DOI： 10.1002/pola.24430

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：WILEY-V C H VERLAG GMBH  

This article is referred to the clarification of polymerization characteristics of microgel-like network polymer precursor (NPP), closely related to the inhomogeneous polymer network formation, in the free-radical crosslinking (co)polymerization of multivinyl monomers. Firstly, the gelation in free-radical crosslinking allyl benzoate/diallyl terephthalate (DAT) copolymerization governed by Flory-Stockmayer gelation theory was explored in the presence of ethylene glycol dimethacrylate (EGDMA) as a typical multivinyl monomer. Since the copolymerizability of allyl monomer with methacrylate monomer is very poor, the crosslinking EGDMA polymerization accompanied by in situ nanogel- or microgel-like methacrylate-NPP formation was preceded. Secondly, DAT polymerization was carried out with in situ inhomogeneous network formation by a preceded crosslinking EGDMA polymerization. The structures of resulting NPPs were characterized by SEC-MALLS-viscometry. Here, the preceded in situ methacrylate-NPP formation promoted the gelation, never leading to delayed gelation. Finally, our aforementioned discussion was extended to the preparation of novel core-shell type allylic nanoparticles based on crosslinking multiallyl/multivinyl copolymerizations.

DOI： 10.1002/masy.201000124

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

The present study is an extension of our preceding work on gelation behavior. We observed no substantial difference in the actual gel points among three isomeric diallyl phthalates: diallyl phthalate, diallyl isophthalate and diallyl terephthalate. The resulting network polymer precursors (NPPs) were characterized by size-exclusion chromatography with both multiangle laser light scattering and viscometry. It is of note that the structure of NPP, consisting of oligomeric primary polymer chains, becomes core-shell type dendritic or nanogel-like with the progress of polymerization. The nanogel-like NPPs can then collide with one another to form cross-links, eventually leading to gelation. Although the concentration of NPP should be high at the conversion close to the gel point, the dilution of NPP by adding monomer could prevent the cross-link formation among NPPs, and consequently lead to the successive growth of high-molecular-weight NPP from a nanogel to a microgel. The further growth of the microgel as an inhomogeneous NPP with high cross-link density could eventually reach an extremely inhomogeneous network polymer. These processes were pursued as typical examples using the bulk polymerization of DAT. Polymer Journal (2010) 42, 923-927; doi: 10.1038/pj.2010.96; published online 27 October 2010

DOI： 10.1038/pj.2010.96

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Allyl monomers polymerize with difficulty and their polymerization yields polymers of medium molecular weight or oligomers. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry is a powerful tool for structural identification of oligomers; therefore, we aimed to use it to collect direct evidence for a full mechanistic discussion, including initiation and termination reactions. In the course of our investigation, which was concerned with the temperature dependence of the reinitiation reactivity of resonance-stabilized monomeric allyl radicals and was especially focused on polymerization behavior at elevated temperatures, we found by chance that any direct contribution of cumyloxy radicals to the initiation reaction was not observed in the polymerization of allyl benzoate with dicumyl peroxide (a typical peroxide initiator) at elevated temperatures. However, a methyl radical initiation preceded by beta-scission of cumyloxy radicals predominantly occurred. This finding was extended to the generalization of an initiation reaction mechanism in allyl polymerization with organic peroxide initiators at elevated temperatures. Polymer Journal (2010) 42, 716-721; doi:10.1038/pj.2010.66; published online 4 August 2010

DOI： 10.1038/pj.2010.66

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Our previous mechanistic discussion of the free-radical crosslinking monoallyl/diallyl copolymerizations was extended to the cationic crosslinking monoepoxide/diepoxide copolymerizations, typically including 1,2-epoxycyclohexane (ECH) as a monoepoxide and bis[3,4-epoxycyclohexylmethyl] adipate (BECHMA) as a diepoxide crosslinker. In the cationic polymerization, oligomer is usually obtained because of the occurrence of characteristic chain-forming reactions. Therefore, cationic crosslinking monoepoxide/diepoxide copolymerizations could be in the category of the network formation through free-radical crosslinking monoallyl/diallyl copolymerizations. Thus, the gelation behavior was discussed by comparing the actual gel points with the theoretical ones; the greatly delayed gelation from theory was observed. Then, the resulting network polymer precursors (NPPs) were characterized by SEC-MALLS-viscometry to clarify the cationic crosslinking ECH/BECHMA copolymerization mechanism. Notably, the correlation lines of molecular weight versus elution volume were specific for the NPPs obtained at a high conversion close to the gel point as compared with those obtained by the free-radical crosslinking monoallyl/diallyl copolymerization. This may be ascribed to the occurrence of intramolecular and intermolecular chain transfer reactions characteristic of cationic polymerization; the chain transfer reactions involve the intramolecular and intermolecular nucleophilic attack of ether oxygen or terminal hydroxyl oxygen in the NPPs to a terminal growing cation that leads to the formation of not only the loop-but also the crosslink-structures containing NPPs, providing fragile ultrahigh-molecular-weight NPP in the SEC columns. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4445-4455, 2010

DOI： 10.1002/pola.24234

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

In free-radical cross-linking (co)polymerization of common multivinyl monomers it has been conceived that the greatly delayed gelation from theory is due to microgel formation. This was discussed by pursuing the gelation in free-radical cross-linking polymerization of diallyl terephthalate (DAT) in the coexistence of a preceded cross-linking polymerization of ethylene glycol dimethacrylate accompanied by in situ methacrylate network-polymer-precursor (NPP) formation since in DAT polymerization the primary-polymer-chain forming reaction could be controlled by the allylic hydrogen abstraction of growing polymer radical from allyl monomer, and thus, any gel effect inducing the complication of the polymerization system is not observed at all. Thus, the preceded in situ methacrylate NPP formation promoted the gelation, never leading to delayed gelation. The role of high-molecular-weight NPPs ranging from an ideal NPP to a nanogel-like NPP on the gelation in DAT polymerization was then pursued by SEC-MALLS-viscometry; the addition of high-molecular-weight NPPs clearly promoted the gelation, and strikingly, the role of nanogel-like NPP was never as an inactive polymer particle leading to a delayed gelation.

DOI： 10.1021/ma100824j

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

No difference in the actual get points was substantially observed among three isomeric diallyl phthalates such as diallyl phthalate (DAP), diallyl isophthalate, and diallyl terephthalate (DAT); this interesting gelation behavior was discussed further in terms of the correlation between gelation and the difference in cyclization modes, and also, the difference in reactivity between the uncyclized and cyclized radicals for cross-linking. In the present work, we tried to extend the preceding discussion to the polymerization of triallyl trimellitate (TAT) because the molecular structure of TAT is presumed to essentially involve the characteristics of three isomeric diallyl phthalates and, therefore, the enhanced gelation was expected in TAT polymerization. However, no enhancement of gelation was observed. For a full understanding of the gelation in multiallyl cross-linking polymerization, we explored further the polymerizations of DAP, DAT, and TAT, especially focusing on the characterization of resultant network polymer precursors (NPPs) using SEC-MALLS-viscometry providing the correlation of [eta] versus M(w) of fractionated samples. Notably, the structure of NPP consisting of oligomeric primary polymer chains generated from specific allyl polymerization would become core-shell type dendritic with the progress of polymerization. The correlation between delayed gelation and decreased reactivity of dendritic NPP for intermolecular cross-linking is discussed. Conclusively, the reactivity for intermolecular cross-linking between NPPs decreased with the progress of polymerization leading to a delayed gelation. (c) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2871-2881, 2009

DOI： 10.1002/pola.23378

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

Allyl monomers polymerize only with difficulty and yield polymers of medium-molecular-weight or oligomers. This is attributable to "degradative monomer chain transfer." However, the well-known allyl polymerization mechanism is based on only the kinetic data but any structural identification is not given. Allyl acetate (AAc), a most typical allyl monomer, was polymerized radically and the resultant oligomeric poly(AAc)s were characterized using MALDI-TOF-MS spectrometry in order to reassess the AAc polymerization mechanism proposed by Litt and Eirich. The induced decomposition of benzoyl peroxide by both growing polymer radical and monomeric allyl radical was presumed but it was never of importance. Then, the fate of resonance-stabilized monomeric allyl radical generated via monomer chain transfer of growing polymer radical was pursued in terms of the competition between the initiation of a new polymer chain and the chain stopping reaction of a growing polymer radical providing monomeric allyl groups as the initial and terminal end-groups, respectively. The monomer chain transfer constant was estimated to be 3.73 x 10(-2) from the P(n) value of poly(AAc) obtained at a low initiator concentration where the coupling termination of growing polymer radical with monomeric allyl radical was negligible.

DOI： 10.1295/polymj.PJ2008174

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Nonfilled triallyl isocyanurate (TAIC) cured resin obtained directly by polymerization of TAIC monomer was too brittle for practical use. The brittleness of cross-linked resins has been thought to be due to the inhomogeneity of their network structures, which consist of colloidal particles as evidenced by electron microscopy. However, the complete loss of flexibility of poly(TAIC) chain does not satisfy the prerequisite of locally enhanced occurrence of intramolecular cross-linking reaction inducing microgelation to form a colloidal particle. Therefore, the correlation between brittleness and network structure of TAIC resins was further discussed, especially focusing on the characterization of resulting TAIC network polymer precursors (NPPs) by size-exclusion chromatography (SEC)-multiangle laser light scattering (MALLS) -viscometry since the ordinary explanation for the brittleness of cross-linked resin does not appear to be the true explanation for TAIC resin's extreme brittleness. Thus, an alternative explanation for the brittleness of TAIC resins is provided: insufficient growth of the network structure of TAIC resin because of steric hindrance of the cross-linking reaction between sterically crowded growing polymer radical and pendant allyl groups belonging to the rigid primary polymer chain. This imperfection of cross-linking, providing not only insufficient network structure formation but also incorporation of abundant dangling chains into network polymer, could be one of the principal causes of brittleness, even for common cross-linked resins.

DOI： 10.1021/ma800974s

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Butyl vinyl ether (BVE) was polymerized radically, and the resultant oligomeric poly(BVE)s were characterized mainly using MALDI-TOF-MS spectrometry. For a further structural identification, the poly(BVE) obtained in bulk was subsequently subjected to H-1 NMR measurement. Notably, an intensive peak assignable to -CH2C(=O)CH2- protons was observed unexpectedly although a peak assignable to -CHO proton as the terminal end-group generated via beta-scission of growing polymer radical as a presumed chain-end forming reaction appeared only weakly. Thus, a plausible chain-end forming reaction would be the intramolecular (backbiting) hydrogen abstraction to form mid-chain radical which subsequently undergoes beta-scission resulting in oligomeric poly(BVE) radical was checked by using toluene as a solvent having labile hydrogen. The dependence of the degree of polymerization on initiator concentration was examined because the occurence of primary radical termination was remarkable, probably leading to reduce chain length. Finally, the reinitiation reaction by butyl group generated via beta-scission of mid-chain radical was pursued.

DOI： 10.1021/ma800949q

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Language：Japanese   Publisher：Japan Thermosetting Plastics Industry Association  

Diene rubber is regarded as internal olefinic multiallyl monomers linked allyl groups (-CH=CR-CH<SUB>2</SUB>- : R = H or CH<SUB>3</SUB>) with methylene units (-CH<SUB>2</SUB>-) and thus, liquid diene rubbers such as liquid polybutadiene rubber (LBR) and liquid polyisoprene rubber (LIR) as nonconjugated polyene oligomers are called as "internal olefinic multivinyl crosslinkers". So this work is concerned with the free-radical crosslinking copolymerizations of (meth) acrylic monomers with LBR and LIR in order to examine the role of "internal olefinic multivinyl crosslinker" as an extension of our continuing studies concerned with the mechanistic discussion of network formation in the free-radical crosslinking polymerization and copolymerization of multivinyl monomers. The present discussion was focused on the elucidation of the competitive occurrence of both addition reaction to internal double bonds and abstraction reaction of allylic hydrogens in LBR and LIR by growing polymer radical.

DOI： 10.11364/networkpolymer1996.29.64

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

It is well known that allyl monomers polymerize only with difficulty and yield polymers having low molecular weights, i.e., oligomers. Inevitably, free-radical multiallyl crosslinking polymerization provides network polymers consisting of oligomeric primary polymer chains, i.e., having abundant dangling chains. This led to the development of novel flexible network polymers such as amphiphilic network polymers (I) consisting of short primary polymer chains and long crosslink units with opposite polarities, simultaneous interpenetrating networks (II) consisting of both polyurethane (PU) and polymethacrylate (PM) networks with oligomeric primary polymer chains, and network polymers (III) consisting of centipede-type primary polymer chains. Thus, the solution copolymerizations of benzyl methacrylate with tricosaethylene glycol dimethacrylate in the presence of lauryl mercaptan yielded I consisting of nonpolar, short primary polymer chains and polar, long crosslink units. The opposite type of I was prepared by the copolymerization of 2-hydroxyethyl methacrylate, a polar monomer having a hydroxyl group, with heneicosapropylene glycol dimethacrylate, a nonpolar monomer having a poly(oxypropylene) unit. The equimolar polyaddition crosslinking reaction of poly(methyl methacrylate-co-2-methacryloyloxyethyl isocyanate) with tri(oxytetramethylene) glycol, leading to PU networks, and the free-radical crosslinking copolymerization of methyl methacrylate with tri(oxytetramethylene) dimethacrylate in the presence of CBr4, leading to PM networks, were progressed simultaneously, providing II formed via the topological crosslink between PU and PM network structures. The post-copolymerizations of oligomeric allyl methacrylate/alkyl methacrylate precopolymers, having different amounts of pendant allyl groups and different molecular weights, with allyl benzoate/vinyl benzoate monomer mixtures were conducted to give III.

DOI： 10.1007/s00289-006-0595-2

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Language：English   Publisher：Kansai University  

Attempts to improve the toughness of triallyl isocyanurate (TAIC) resins were unsuccessful using the procedures developed for diallyl phthalate (DAP) resins as typical allyl resins by considering microinhomogenization of the DAP resin during polymerization beyond the gel-point conversion. This demonstrates the difference in network structure of TAIC and DAP resins. The structure of branched TAIC prepolymer was characterized as dendritic by SEC-MALLS-viscometry. Thus, an alternative explanation for the brittleness of TAIC resins is provided: the insufficient growth of the network structure of TAIC resin because of steric hindrance on the crosslinking reaction between sterically crowded growing polymer radical and pendant allyl groups belonging to the rigid primary polymer chain.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The control of the intermolecular cross-linking reaction in free-radical cross-linking monovinyl/divinyl copolymerizations resulting in amphiphilic network polymers was attempted by the aid of amphiphilic nature of primary polymer chains and cross-link units with opposite polarities. First, benzyl methacrylate (BzMA)/tricosaethylene glycol dimethacrylate (PEGDMA-23) (95/5) copolymerizations in 1,4-dioxane (DO) and DO/H2O (85/15) mixed solvent were investigated. The assembly of short primary polymer chains induced the restricted motion of propagating polymer radical, leading to a suppressed increment of molecular weight with conversion. Second, 2-hydroxyethyl methacrylate (HEMA)/henicosapropylene glycol dimethacrylate (PPGDMA-21) (95/5) copolymerizations in DO, DO/H2O (80/20) mixture, and DO/H2O (70/30) mixture were explored. The assembly of nonpolar cross-link units led to an enhanced occurrence of intermolecular cross-linking reaction. Moreover, the assembly of polar primary polymer chains consisting of poly(HEMA) in DO suppressed the cross-linking reaction as is the case with BzMA/PEGDMA-23 (95/5) copolymerizations. Then, the solvent effect on gelation was generalized by using various solvents. Especially, our attention was focused on acetonitrile (ACN) and N,N-dimethylformamide (DMF) as solvents because the resulting gel in HEMA/PPGDMA-21 (95/5) copolymerization swelled in DMF but shrank in ACN despite almost the same solubility parameters for both solvents. Thus, both primary polymer chains and cross-link units of amphiphilic prepolymers would not assemble in DMF, whereas primary polymer chains having hydroxyl groups would assemble in ACN. The assembly of short primary polymer chains in ACN led to a suppressed increment of molecular weight with conversion as a reflection of the restricted motion of propagating polymer radical. Conclusively, the assembly of short primary polymer chains suppressed the occurrence of intermolecular cross-linking reaction, whereas the assembly of long cross-link units promoted it.

DOI： 10.1021/ma0479262

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The equimolar polyaddition cross-linking reaction of poly(methyl methacrylate-co-2-methacryloyloxyethyl isocyanate) with tri(oxytetramethylene) glycol leading to polyurethane (PU) networks was carried out in methyl benzoate at a 0.1 mol/L concentration of functional groups at 80 degreesC. Simultaneously, the free-radical cross-linking copolymerization of methyl methacrylate with tri(oxytetramethylene) dimethacrylate leading to polymethacrylate (PM) networks was progressed at a dilution of 1/10 in the presence of CBr4 as a chain transfer agent. The simultaneous interpenetrating networks (SINs) were formed via the topological cross-links between PU and PM network structures introduced by the respective intramolecular cross-linking reactions. Under the same polymerization conditions, no gelation was observed for respective cross-linking homopolymerizations leading to PU and PM homo-networks because respective intramolecular cross-linking reactions would be enhanced at a diluted solution. The topological cross-link formation between PU and PM network polymer precursors was pursued by SEC monitored with a multichannel UV-vis spectrometer device. The enhanced occurrence of intermolecular cross-linking via the topological cross-link formation was reflected on the variations of both the UV-vis monitored SEC curves and the molecular weights of the resulting PU and PM network polymer precursors with conversion. In addition, the respective actual gel points were compared with the corresponding theories for PU and PM networks formation or gelation. The swelling ratio of the resulting gel was quite high, suggesting a rather low cross-link density of PU/PM SIN produced through the topological cross-link formation between PU and PM network polymer precursors.

DOI： 10.1021/ma040073t

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

d-Bornyl methacrylate (BoMA) was chosen as a typical example of bulky monomethacrylate monomers, the polymerization of which led to the formation of a rigid polymer chain. To discuss the effect of primary polymer chain rigidity on intramolecular cyclization, we compared the solution copolymerization results of BoMA with 1 mol % ethylene dimethacrylate (EDMA; n = 1) and poly(ethylene glycol dimethacrylate) [CH2=C(CH3)CO(OCH2CH2),,OCOC(CH3)=CH2, n = 9 (PEGDMA-9)] with those of methyl methacrylate (MMA) with 1 mol % EDMA and PEGDMA-9; the dependence of the weight-average degree of polymerization on conversion for the former BoMA copolymerization systems was completely opposed to that for the latter MMA systems, and this was a reflection of a reduced occurrence of intramolecular cyclization caused by the rigidity of the primary polymer chain. The effect of primary polymer chain rigidity on intramolecular crosslinking was discussed through a comparison of both BoMA/EDMA and MMA/EDMA copolymerizations. The correlations of the intrinsic viscosity, root-mean-square (rms) radius of gyration, and second virial coefficient with the molecular weight were examined for both BoMA/EDMA (90/10) and MMA/ EDMA (90/10) copolymerizations in a dilute solution because microgelation was observed in solution MMA/EDMA (90/10) copolymerization as a reflection of a locally extensive occurrence of intramolecular crosslinking. The logarithmic plots of both the intrinsic viscosity and rms radius of gyration versus the molecular weight for MMA/EDMA copolymerization were compared with those for the corresponding BoMA/EDMA copolymerizations. The second virial coefficients were greater than 10(-5) mol cm(3) g(-2) for BoMA/EDMA copolymers, even when the conversion was very close to the gel point, whereas they were quite low, that is, less than 10(-5) mol cm(3) g(-2), for an MMA/EDMA copolymer obtained at more than 15% conversion. These were ascribed to a suppressed occurrence of intramolecular crosslinking, a reflection of the lessened flexibility of the polymer main chain and a steric effect due to the bulky d-bornyl groups. @ 2004 Wiley Periodicals, Inc.

DOI： 10.1002/app.20976

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

As part of a series of our works concerned with the elucidation of the crosslinking polymerization mechanism leading to the interpenetrating polymer network (IPN) formation, in which IPN consists of both polyurethane (PU) and polymethacrylate (PM) networks, this article deals with the polyaddition crosslinking reactions of poly(methyl methacrylate-co-2-methacryloyloxyethyl isocyanate) poly-(MMA-co-MOI) [MMA/MOI = 99/1] as a novel multifunctional polyisocyanate with poly(oxytetramethylene) glycol [H-(OCH2CH2CH2CH2)(n)-OH (n = 28)] (POTMG-28) in the presence of two types of linear PMs, differently miscible with the resulting PU networks, leading to semi-IPN formation. Thus, poly(MMA-co-MOI) was prepared by the radical copolymerization of MOI with MMA in the presence of CBr4 as a chain-transfer agent. No influence of the linear PM on the rate of polyaddition crosslinking reaction was observed. The actual gel points were compared with the theoretical ones calculated according to Macosko's equation: the deviation of the actual gel point from the theoretical one was rather small, close to the ideality, and the delayed gelation from theory tended to become a little smaller in the presence of PM. These are discussed mechanistically to deepen the understanding of the PU network formation in the presence of a linear PM resulting in semi-IPN, along with the data of the intrinsic viscosities of resulting prepolymers. To collect a direct evidence of semi-IPN formation, we attempted to pursue the incorporation of the linear PM into the resulting PU networks by H-1-NMR and UV-vis spectroscopy; in the latter case, the copolymers containing a small amount of pyrenyl methacrylate were used as linear PMs because the pyrenyl group was employed as the probe for UV-vis spectroscopic determination of the amount of the incorporated PM. The swelling ratio of the gel became lower in the presence of a linear PM. All data for the polyaddition crosslinking reactions of poly(MMA-co-MOI) with POTMG-28 in the presence of PM, along with the mechanistic discussion, demonstrate that the freely compatible molecular interaction would lead to a true semi-IPN formation as a result of the good miscibility between PU networks and a linear PM. (C) 2004 Wiley Periodicals, Inc.

DOI： 10.1002/app.21030

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

2,2'-Azobis[N-(2-propenyl)-2-methylpropionamide] (APMPA) having two carbon-carbon double bonds and an azo group was copolymerized with vinyl benzoate (VBz) at 60 degreesC, providing an azo groups containing VBz/APMPA prepolymer or crosslinked polymer which acts as a soluble or insoluble polymeric azo initiator, respectively. The gelation in VBz/APMPA (90/10 mol/mol) copolymerization was discussed briefly in order to reveal the characteristic polymerization behaviour of APMPA as a novel crosslinker. Then, the resulting poly(VBz-co-APMPA)s as prepolymers or crosslinked polymers were thermally decomposed at elevated temperatures in the presence of lauryl mercaptan (LM) as a chain transfer agent; thus, the polymeric radicals generated through the cleavage of azo crosslinks would undergo the chain transfer reaction with LM to give primary polymer chains. This will provide a new approach to estimate the primary polymer chain length of vinyl-type network polymers by cutting all crosslinks in the network at the gel point as defined for the derivation of Stockmayer's equation. (C) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2004.08.015

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Novel amphiphilic network polymers consisting of nonpolar, short primary polymer chains and polar, long crosslink units were prepared, and the swelling behavior of resulting amphiphilic gels is discussed by focusing on the influence of characteristic dangling chains; that is, benzyl methacrylate (BzMA) was copolymerized with tricosaethylene glycol dimethacrylate [CH2=C(CH3)CO(OCH2CH2)(23)OCOC(CH3)=CH2, PEGDMA-23] in the presence of lauryl mercaptan as a chain-transfer agent because BzMA forms nonpolar, short primary polymer chains and PEGDMA-23 as a crosslinker contains a polar, long poly(oxyethylene) unit. The enhanced incorporation of dangling chains into the network polymer was brought by shortening the primary polymer chain length, and copolymerization with methoxytricosaethylene glycol methacrylate, a mono-ene counterpart of PEGDMA-23, enforced the incorporation of flexible dangling poly(oxyethylene) chains into the network polymer, although the former dangling chains as terminal parts of primary poly(BzMA) chains were rather rigid. Then, the influence of characteristic dangling chains on the swelling behavior of amphiphilic gels was examined in mixed solvents consisting of nonpolar t-butylbenzene and polar methanol. The profiles of the solvent-component dependencies of the swelling ratios were characteristic of amphiphilic gels. The introduction of dangling poly(oxyethylene) chains led not only to an increased swelling ratio but also to sharpened swelling behavior of amphiphilic gels. The swelling response of amphiphilic gels was checked by changing the external solvent polarity. The dangling chains with freely mobile end segments influenced the swelling response of gels. The amphiphilic gels with less entangled, collapsed crosslink units exhibited faster swelling response than the ones with more entangled, collapsed primary polymer chains. (C) 2004 Wiley Periodicals, Inc.

DOI： 10.1002/pola.20054

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

Here, as part of our continuing studies concerned with the network formation mechanism in the free-radical cross-linking polymerization and co-polymerization of multivinyl monomers, we briefly reviewed the development of a variety of novel polymers originated from multiallyl cross-linking polymerization. The formation processes of the ideal network polymer governed by the Flory-Stockmayer gelation theory, the microgel and the semi-interpenetrating polymer network (senti-IPN) were employed to develop novel polymers by a combination with allyl polymerization leading to short polymer chain formation and intramolecular cross-linking as a key reaction of network formation Generating network structure. These include amphiphilic pre-polymers and network polymers derived from ideal network polymer, core/corona nanoparticles derived from pseudo-microgel, topological polymers as semi-IPN precursors and centipede polymers as primary polymer chains of network polymers having abundant dangling chains.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

As part of our continuing studies concerned with the elucidation of the crosslinking polymerization mechanism leading to interpenetrating polymer network (IPN) formation, in which IPNs consist of both polymethacrylates and polyurethane (PU) networks, this article explores the polyaddition crosslinking reactions of multifunctional poly(methyl methacrylate-co-2-methacryloyloxyethyl isocyanate) [poly(MMA-co-MOI)] [MMA/MOI = 90/10] with various diols leading to PU network formation. Thus, the equimolar polyaddition crosslinking reactions of poly(MMA-co-MOI) with ethylene glycol (EG), 1,6-hexane diol, and 1,10-decane diol (DD) were carried out in N-methyl pyrrolidone at a 0.25 mol/L isocyanate group concentration at 80 degreesC. The second-order rate constants decreased from EG to DD. The deviation of the actual gel point from the theoretical one was smaller from EG to DD. The intrinsic viscosity of resulting prepolymer demonstrated almost no variation with progressing polymerization for the EG system, whereas it gradually increased with conversion for the DD system. Close to the gel point conversion it increased rather drastically for both systems. The swelling ratio of resulting gel was higher from EG to DD. These are discussed mechanistically in terms of the significant occurrence of intramolecular cyclization and intramolecular crosslinking reactions leading to shrinkage of the molecular size. (C) 2003 Wiley Periodicals, Inc.

DOI： 10.1002/pola.10917

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Solution copolymerizations of 2-hydroxyethyl methacrylate (HEMA), a polar monomer having a hydroxyl group, with 5 mol % (corresponding to 35.7 wt %) heneicosapropylene glycol dimethacrylate (PPGDMA-21), a nonpolar monomer having a poly(oxypropylene) unit, were carried out in MeOH at a dilution of 2/3 in the presence of different amounts of lauryl mercaptan as a chain transfer agent, providing novel amphiphilic vinyl-type network polymers consisting of polar, short primary polymer chains and nonpolar, long cross-link units. The vinyl-type network polymers formed via highly branched prepolymers have abundant dangling chains as their characteristic feature, especially when the primary polymer chain length is short, because both terminal parts of primary polymer chain would be dangling chains. The amphiphilicity of the resulting gels was checked by measuring their swelling ratios in the mixed solvents consisting of nonpolar tert-butylbenzene (t-BB) and polar MeOH; thus, with an increase in the MeOH volume percent, the gels shrank to the smallest swelling ratio at the start point (i.e., in pure t-BB), swelled gradually and then rather sharply beyond 20 vol %, reached the maximum swelling at about 70 vol %, and then shrank gradually up to a rather high swelling ratio at the terminal (i.e., in pure MeOH). The profiles of the solvent component dependencies of the swelling ratios are characteristic of novel amphiphilic gels. The conversion dependency of the characteristic swelling behavior suggests that the response of the gel obtained at an earlier stage of gelation was sharper than that of the gel obtained at a late stage of gelation. The influence of H2O on the characteristic swelling behavior of resulting amphiphilic gels was examined by measuring their swelling ratios in the mixed solvents consisting of MeOH/H2O or acetone/ H2O in order to collect information about the role of cross-link units on the swelling behavior of amphiphilic gel.

DOI： 10.1021/ma0302715

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Microgel-like poly(allyl methacrylate) (PAMA nanosphere) was prepared by the emulsion polymerization of AMA as the reactive crosslinked polymer nanosphere with abundant pendant allyl groups. The terpolymerization of PAMA nanosphere with allyl benzoate (ABz) and vinyl benzoate (VBz) was conducted in bulk using benzoyl peroxide as initiator at 80 degreesC. The gelation depended on the feed ABz/VBz molar ratio since the molecular weights of resulting poly(ABz-co-VBz)s that act as the bridges increased with an increase in the mole fraction of VBz in the feed monomer. Beyond the gel point, the sol was rapidly incorporated into the gel and the increasing tendency of the gel fraction became steeper from 70 to 95 mol% of VBz as a reflection of increased chain length of bridge between PAMA nanospheres. Moreover, the swelling ratio became lower with increasing the mole percentage of VBz in the feed monomer. These results would support the preferential incorporation of PAMA nanosphere into the gel and the longer bridge can capture more nanospheres to give a much shrunken gel. (C) 2003 Elsevier Ltd. All rights reserved.

DOI： 10.1016/S0014-3057(03)00124-1

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Network-polymer precursors obtained in various crosslinking monovinyl/divinyl copolymerization systems, including benzyl methacrylate/1,6-hexanediol dimethacrylate, benzyl acrylate (BzA)/1,6-hexanediol diacrylate (HDDA), and vinyl benzoate/divinyl adipate, were subjected to degradation during elution through size exclusion chromatography (SEC) columns, although the copolymerizations were conducted under specified conditions where the factors for the greatly delayed gelation from the Flory-Stockmayer gelation theory were reduced. The most remarkable degradation was observed for the BzA/HDDA copolymerization, which provided prepolymers with the most flexible backbone chains. Thus, the BzA/HDDA precopolymers were chosen, and their degradation behavior during elution through SEC columns was explored in detail as one of the representatives of vinyl-type network-polymer precursors. The results were correlated with the structural parameters of network-polymer precursors, including primary polymer chain length, branched structure, and multiple crosslink or network structure. The degradation became more remarkable with decreased primary polymer chain length, that is, the increment of branching, whereas reduced degradation was observed with the incorporation of loop and network structures into the prepolymer. (C) 2003 Wiley Periodicals, Inc.

DOI： 10.1002/app.12778

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

At the start of our research program concerned with the elucidation of the crosslinking polymerization mechanism leading to interpenetrating polymer network (IPN) formation, in which IPNs consist of both polymethacrylates and polyurethane (PU) networks, this article deals with the polyaddition crosslinking reaction leading to PU network formation. Therefore, 2-methacryloyloxyethyl isocyanate (MOI) was radically copolymerized with methyl methacrylate (MMA) in the presence of CBr4 as a chain-transfer agent. The resulting poly(MMA-co-MOI)s, having pendant isocyanate (NCO) groups as novel multifunctional polyisocyanates, were used for polyaddition crosslinking reactions with ethylene glycol as a typical diol. The second-order rate constants depended on both the functionality of poly(MMA-co-MOI) and the NCO group concentration. The actual gel points were compared with the theoretical ones calculated according to Macosko's equation; the deviation of the actual gel point from the theoretical value became more remarkable for a greater functionality of poly(MMA-co-MOI) and at a lower NCO group concentration or at a lower poly(MMA-co-MOI) concentration. These are discussed mechanistically, with consideration given to the significance of intramolecular cyclization and intramolecular crosslinking reactions leading to the shrinkage of the molecular size of the prepolymer, along with the data of the intrinsic viscosities of resulting prepolymers and the swelling ratios of resulting gels. (C) 2003 Wiley Periodicals, Inc.

DOI： 10.1002/pola.10615

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Language：English  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The effect of physical interaction through hydrogen bonds on the intermolecular crosslinking reaction leading to the promoted gelation in free-radical crosslinking monovinyl/divinyl copolymerizations was discussed froth the standpoint of the control of network formation. The solution copolymerizations of benzyl methacrylate (BzMA) with 2 mol%, of 1,6-hexanediol dimethacrylate in t-butylbenzene were conducted in the absence and presence of different amounts of mono(2-methacryloyloxyethyl) succinate (MMOES). Gelation was promoted by the addition of MMOES and the ratio of the actual gel point to the theoretical one became smaller: this would be related to the formation of hydrogen bonds between carboxyl groups introduced into prepolymer and growing polymer radical. As an extension of the above discussion, we treated the effect of hydrogen bonds on the gelation in the crosslinking BzMA/triicosaethylene glycol dimethacrylate copolymerization. The addition of MMOES obviously promoted the gelation. The ratio of the actual gel point to the theoretical one calculated according to Stockmayer's equation [J. Chem. Phys. 12 (1944) 125] was obtained as 1.9, very close to unity. (C) 2002 Elsevier Science Ltd. All rights reserved.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

The dehydrogenation of ethylbenzene over a vanadium oxide-loaded MgO catalyst was investigated using carbon dioxide. The styrene yield in the presence of carbon dioxide was 2.5 times higher than that in the absence of carbon dioxide (argon atmosphere) at 823 K, indicating that carbon dioxide markedly promoted the dehydrogenation of ethylbenzene. At 873 K, the same catalyst afforded the highest styrene yield, 73.8% with a selectivity of 90.1%, in the presence of carbon dioxide. In order to elucidate the role of carbon dioxide in this reaction, characterization of the catalyst was carried out via methods such as temperature-programmed reduction, temperature-programmed reaction with carbon dioxide, and UV-visible, FT-IR, and XRD spectroscopies. Carbon dioxide behaved as an oxidant for the vanadium species, and the surface vanadium species were kept in a high oxidation state with carbon dioxide during the dehydrogenation reaction. Active phases of vanadium in the dehydrogenation reaction were believed to be V5+ species in V2O5 or Mg3V2O8 on highly dispersed MgO. The reduced species, V4+ and V3+, were less reactive sites for the dehydrogenation. (C) 2002 Elsevier Science (USA).

DOI： 10.1006/jcat.2002.3593

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

As an extension of our continuing studies concerned with the free-radical cross-linking polymerization and copolymerization of multivinyl compounds, this article deals with the gelation in the copolymerization of allyl methacrylate (AMA), a typical unsymmetrical divinyl compound containing two types of vinyl groups such as methacryloyl and allyl ones having quite different reactivities, with several alkyl methacrylates, especially focusing on the steric effect of long-chain alkyl groups. Thus, AMA was copolymerized in bulk with methyl methacrylate (MMA), butyl methacrylate (BMA), lauryl methacrylate (LMA), and stearyl methacrylate (SMA) using azo-initiator at 50 degreesC in the presence of lauryl mercaptan as a chain transfer agent. The actual gel point was compared with the calculated one according to Stockmayer's equation by tentatively supposing equal reactivity of both vinyl groups. In the copolymerizations with LMA and SMA, the suppressed occurrence of intermolecular cross-linking reaction caused by the steric effect of long-chain alkyl groups was clearly observed as a reflection of delayed gelation, whereas the copolymerizations with MMA and BMA were roughly governed by the predominant occurrence of intermolecular cross-linking. These were supported by the conversion dependencies of the molecular-weight distribution profiles, the correlation curve of molecular weight versus elution volume, and the correlation of intrinsic viscosity versus molecular weight of resulting precopolymers. (C) 2002 Elsevier Science Ltd. All rights reserved.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

2,2'-Azobis[N-(2-propenyl)-2-methylpropionamide] (APMPA) with two carbon-carbon double bonds and an azo group was copolymerized with vinyl benzoate (VBz) at 60 degreesC, resulting in azo groups containing VBz/APMPA prepolymers and crosslinked polymers as soluble and insoluble polymeric azo initiators, respectively. The polymerization characteristics of APMPA as a novel diallyl monomer were clarified with the rate and degree of polymerization and the monomer reactivity ratios. The gelation behaviors in VBz/APMPA crosslinking copolymerizations were examined in detail with a comparison of the actual gel point and the theoretical gel point calculated according to Stockmayer's equation with the tentative assumption of equal reactivity for both vinyl groups belonging to VBz and APMPA. The effectiveness of the resulting branched or crosslinked poly(VBz-co-APMPA)s as soluble or insoluble polymeric azo initiators, respectively, at providing graft polymers through the cleavage of azo groups at an elevated temperature was examined by the polymerization of allyl benzoate at 120 degreesC. (C) 2001 John Wiley Sons, Inc.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Electron spin resonance spectroscopic studies on the microheterogeneity of crosslinked polymers were performed to ascertain the correlation of the void evaluation of monomethacrylate/dimethacrylate (DMA) cured resins with the microgel formation before gelation in their crosslinking copolymerizations. Lauryl methacrylate (LMA) was added to methyl MA (MMA)/ethylene DMA (EDMA) copolymerization because the addition of LMA reduces the occurrence of intramolecular crosslinking by the steric hindrance of bulky long-chain alkyl groups, leading to the formation of a less densely crosslinked microgel core and a less microheterogeneously crosslinked resin. Then MMA/vinyl laurate (VL)/EDMA terpolymerization was performed because the polymerizability of conjugated methacryloyl groups belonging to MMA and EDMA is markedly high compared with the unconjugated vinyloxycarbonyl group of VL. Thus, enhanced microheterogeneity for MMA/VL/EDMA terpolymerization would be induced as compared with MMA/EDMA copolymerization. Finally, allyl MA (AMA) and vinyl MA C(SIMA) crosslinkers were used in place of EDMA because in the polymerizations of AMA and VMA having two types of carbon-carbon double bonds of different reactivities there was no microgelation observed up to the gel-point conversion. (C) 2001 John Wiley & Sons, Inc.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

The usefulness of the ReactIR(R) reaction analysis system as a powerful tool to in-situ monitor the kinetics of the emulsion polymerization of viny monomers was verified by comparison with the conventional gravimetric method and by checking the rate dependencies on initiator and surfactant concentrations in the emulsion polymerization of butyl methacrylate (BMA). The system was then applied to the kinetic monitoring of emulsion crosslinking copolymerizations of monomethacrylate and dimethacrylate, including methyl methacrylate/ethylene dimethacrylate and BMA/1,6-hexanediol dimethacrylate systems of different hydrophilicities.

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The anomalous popcorn formation in the presence of a large amount of lauryl mercaptan as a chain transfer agent was explored in the free-radical crosslinking copolymerization of benzyl methacrylate with neopentyl glycol dimethacrylate, Thus, the radical accumulation during proliferous polymerization was pursued ESR-spectroscopically and a brief mechanistic discussion is described. (C) 2001 Elsevier Science Ltd. All rights reserved.

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Benzyl methacrylate (BzMA) was copolymerized radically with polyethylene glycol dimethacrylate [CH2=C(CH3)CO(OCH2CH2)(23)OCOC(CH3)=CH2] (PEGDMA-23) to provide novel amphiphilic polymers as precursors of crosslinked polymers governed by Flory-Stockmayer gelation theory (F-S theory). Thus, BzMA/PEGDMA-23 copolymerizations were conducted under the specified conditions where the occurrence of a thermodynamic excluded volume effect and intramolecular crosslinking as the primary and secondary factors, respectively, for the greatly delayed gelation in the free-radical monovinyl-divinyl copolymerizations was reduced: Firstly, the reasonable applicability of F-S theory was verified by the comparison of the actual gel point with the theoretical one. Secondly, the tailed molecular-weight distribution curves were observed with conversion as a result of the predominant occurrence of intermolecular crosslinking according to F-S theory. Thirdly, the applicability of F-S theory was supported by both the correlations of molecular weight versus elution volume and r.m.s. radius of gyration versus molecular weight, although the molecular size shrinkage of the resulting prepolymers consisting of rather rigid poly(BzMA) chains and flexible polyoxyethylene crosslinks would be enhanced with conversion as a result of increased crosslinking. (C) 2000 Elsevier Science Ltd. All rights reserved.

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2,2'-Azobis(N-(2-propenyl)-2-methylpropionamide) (APMPA) having two carbon-carbon double bonds and an azo group was copolymerized with allyl benzoate (ABz) at 60 degreesC, providing an azo groups containing:: ABz/APMPA crosslinked polymer which may act as an insoluble polymeric azo initiator. The gelation in ABz/ APMPA (70/30 mol/mol) copolymerization was discussed in detail in order to reveal the characteristic polymerization behavior of APMPA as a novel diallyl monomer. The effectiveness of the resulting ABz/APMPA crosslinked polymer to give a soluble graft polymer through cleavage of the azo crosslinkages at an elevated temperature was then examined by polymerizing ABz at 120 degreesC.

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As an extension of our work on the elucidation of the mechanism and control of 3-dimensional network formation in the free-radical crosslinking polymerization and copolymerization of multivinyl compounds with. the aim to molecularly design vinyl-type network polymers, novel amphiphilic polymers were prepared as crosslinked polymer precursors. Thus, benzyl methacrylate, a nonpolar monomer, was copolymerized radically with 5 mol % of triicosaethylene glycol dimethacrylate [CH2=C(CH3)CO(OCH2CH2)(23)OCOC(CH3)=CH2], a polar monomer, in the presence of lauryl mercaptan as a chain transfer agent. The resulting prepolymers (i.e., vinyl-type network-polymer precursors or amphiphilic polymers) were characterized mainly by viscometry using t-butylbenzene (t-BB) and a t-BB/MeOH (80/20) mixture as solvents. The viscosities in the t-BB/MeOH (80/20) mixture were quite high compared with those in t-BB and completely reversed concentration dependencies were observed in the solvents. These are discussed by considering the difference in conformation and the shrinkage of polar, flexible polyoxyethylene units or the entanglement of nonpolar, rigid primary chains. (C) 2000 John Wiley & Sons, Inc.

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Full Paper: As an extension of our continuing studies concerned with the free-radical crosslinking polymerization of multivinyl compounds, this article deals with the gelation in the polymerization of allyl methacrylate (AMA) as a typical unsymmetrical divinyl compound containing two types of vinyl groups such as methacryloyl and allyl ones having quite different reactivities. Thus, AMA was polymerized in hulk or in a 1,4-dioxane solution using an ate-initiator at 50 degreesC in the presence of lauryl mercaptan as chain transfer agent. The actual gel point was compared with the calculated one according to Gordon's equation by tentatively supposing equal reactivity of both vinyl groups. Tailed molecular-weight distribution curves were observed. The swelling ratios of the resulting gels obtained just beyond the gel point was very high. Thus, the intermolecular crosslinking occurred predominantly in the bulk polymerization. Even in the solution polymerization, the occurrence of intramolecular crossing was only a little. This was supported by the uns. radii of gyration and second virial coefficients of resulting prepolymers.
[GRAPHICS]
Dependence of (P) over bar (w) on conversion (see Fig. 1; [LM]/[AMA] = 1/400 (o), 1/200 (Delta), 1/100 (square), and 1/50 (lozenge)).

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The free-radical crosslinking polymerization of diallyl adipate (DAA) was carried out in the presence of poly(benzyl methacrylate) (poly(BzMA)) as a chemically inactive polymer in order to clarify the topological bonding formation between linear polymer and prepolymer before gelation; we found by chance that even at an early stage of the polymerization, the topological bonding was formed between ultra-high molecular weight poly(BzMA) and poly(DAA) prepolymer.

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Triallyl isocyanurate (TAIC), a bulky monomer, was copolymerized radically with sterically unhindered monomers including 1-octene (Oc), vinyl caproate (VCa) and vinyl laurate (VLa). Fineman-Ross plots to evaluate the monomer reactivity ratios showed the great deviation from linear relationships at the low mole fraction of sterically unhindered monomer in the copolymer as a result of a suppressed incorporation of TAIC units into the copolymer chain with an increase in the number of sequential TAIC units, suggesting the sequence length dependence of steric effect on the reactivity of growing polymer radical. (C) 2000 Elsevier Science Ltd. All rights reserved.

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The preliminary study of the effect of physical crosslinking on the gelation in monovinyl/divinyl copolymerizations is described. Thus, mono(2-methacryloxyloxyethyl) succinate was added to the crosslinking copolymerization of butyl methacrylate with 1,6-hexane-diol dimethacrylate and the gelation was explored in terms of the effect hydrogen bonds formed between carboxyl groups introduced into the primary polymer chain.

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Carbon dioxide could oxidize the reduced vanadium oxide species on MgO and keep vanadium species at a high oxidation state, during the dehydrogenation of ethylbenzene to styrene under carbon dioxide, giving a markedly high yield and selectivity of styrene.

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Cyclopolymerization of triallyl isocyanurate (TAIC) as compared with its isomer triallyl cyanurate (TAC) is discussed in terms of the nonterminal units effect caused by the sterically bulky isocyanurate side groups. Thus, the monomer concentration dependence of the: initial residual unsaturation is not explained by considering an ordinary cyclopolymerization mechanism, although TAC polymerization obeyed the mechanism. The effect of the forced introduction of bulkier noncyclic units into the polymer chain on the cyclopolymerizability of TAIC was explored by the copolymerization with allyl dibenzyl isocyanurate, resulting in the enhanced cyclization in conformity with our expectation. (C) 2000 Elsevier Science Ltd. All rights reserved.

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ESR spectroscopic studies on the microheterogeneity of crosslinked polymers were extended to the attempt on a detailed void evaluation of microheterogeneously crosslinked momethacylate/diamethacrylate resins by measuring ESR spectra at lower temperatures, utilizing the interactions between spin probes and side chains. That is, the mobility of copper(II) tetraphenylporphyrin (CuTPP), a spin probe useful for the evaluation of void parts in crosslinked resins, excluded from densely crosslinked network parts to void ones was one found to be much restricted at lower temperatures; this provides a useful tool to allow a detailed evaluation of the void parts. Thus, methyl methacylate (MMA)/ethylene dimethacrylate (EDMA) (mole ratio 70/30) solution copolymerization in toluene at dilution of 2/3 was chosen as a standard copolymerization system to provide the cured resin with void parts. The effect of introducing polar(oxy-ethylene) units was explored to clarify their interaction with the polar central part of th CuTPP their interaction with the polar central part of the CuTPP molecule leading to the restricted mobility of CuTPP. The detailed evaluation of void sizes was done by changing the crosslinker content. The polar interaction was prevented by changing the CuTPP spin probe to a nonpolar one; the nonpolar interaction was verified by adding docosyl methylacrylate having a long-chain alkyl group to the MMA/EDMA copolymerization.

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The temperature effect on the polymerization of triallyl isocyanurate (TAIC) was explored in detail as compared with its isomer triallyl cyanurate (TAC), since TAIC and TAC are commercially important as crosslinking agents with cumonomers, and for aftercuring preformed polymers at elevated temperatures. Thus, the relative rate R-p(TAIC)/R-p(TAC) decreased with temperature, accompanied by the reversed rate feature: as the higher rate for TAIC polymerization has been reported previously at 60 degrees C [3]. No inversion was observed for the gel point and primary chain length, although the difference between TAIC and TAC polymerizations became smaller. The initial residual unsaturation decreased obviously with raised temperature for TAC polymerization, whereas only a slight decrease was observed for TAIC. These results are discussed mechanistically in terms of allyl polymerization and the steric effect caused by the bulky side-chain groups. (C) 2000 Elsevier Science Ltd. All rights reserved.

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Neopentyl glycol dimethacrylate was polymerized in bulk in the presence of lauryl mercaptan as a chain transfer agent, the primary chain length being reduced to a comparable order in allyl polymerization, and the gelation behavior was compared with diallyl terephthalate (DAT) polymerization as a typical example of multiallyl polymerizations. No Trommsdorff effect was observed, even beyond the gel point conversion, in spite of the polymerization of divinyl monomer, as were the cases of the bulk polymerization of multiallyl compounds. The variation of molecular weight distribution curves with conversion was quite similar to DAT polymerization. The deviation of actual gel point from the theoretical one was also similar, Moreover, the swelling ratio of the gel obtained just beyond the gel point was very high. Thus, no substantial difference was observed between allyl and vinyl polymerizations in the case where the primary chain lengths were adjusted to be comparable. In addition, no microgelation occurred up to the gel point. (C) 1999 Elsevier Science Ltd. All rights reserved.

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As part of continuing studies concerned with the elucidation of three-dimensional network formation mechanism in the free-radical crosslinking polymerization of multivinyl compounds, void parts in microheterogeneously crosslinked monomethacrylate/dimethacrylate resins were evaluated by ESR spectroscopy. Thus, the usefulness of copper(II) tetraphenylporphyrin (CuTPP) as a spin probe was verified for the evaluation of void parts under specified polymerization conditions. The correlation between ESR spectra and microheterogeneity of networks formed under various conditions was examined by changing the factors influencing resultant network structures, including monomer concentration, crosslinker content and flexibility of network segments. The mobility restriction of CuTPP by network formation was reduced noticeably under the conditions introducing the inhomogeneous network as a result of the exclusion of CuTPP from densely crosslinked network parts to void ones in cured resins.

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In order to discuss further the significance of the thermodynamic excluded volume effect on gelation in free-radical monovinyl/divinyl crosslinking copolymerizations, allyl benzoate was copolymerized with diallyl terephthalate in the presence of poly(benzyl methacrylate) (poly(BzMA)) having different molecular weights. Thus, the deviation of actual gel point from theoretical one became smaller with an increase in the molecular weight of poly(BzMA) and, moreover, SEC-MALLS measurements clearly afforded supporting evidence for the increased occurrence of intermolecular crosslinking. These results are expected as a result of reduced contribution of the thermodynamic excluded volume effect on gelation. (C) 1999 Elsevier Science Ltd. All rights reserved.

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The emulsion crosslinking polymerization behavior of vinyl methacrylate (VMA) bearing two types of carbon-carbon double bonds, methacryloyl and vinyloxycarbonyl groups, of greatly different reactivities was explored in detail as compared with allyl methacrylate. No gelation occurred even above 90% conversion, whereas the reactive crosslinked-polymer microspheres with abundant pendant vinyloxycarbonyl groups were easily obtained. The weight-average molecular weights, the r.m.s. radii of gyration, the second virial coefficients, the intrinsic Viscosities and H-1 NMR spectra of the resulting vinyl-type reactive microspheres were characteristic of microgel-like polymers.

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The emulsion crosslinking polymerization behavior of vinyl methacrylate (VMA) bearing two types of carbon-carbon double bonds, methacryloyl and vinyloxycarbonyl groups, of greatly different reactivities was explored in detail as compared with allyl methacrylate. No gelation occurred even above 90% conversion, whereas the reactive crosslinked-polymer microspheres with abundant pendant vinyloxycarbonyl groups were easily obtained. The weight-average molecular weights, the r.m.s. radii of gyration, the second virial coefficients, the intrinsic Viscosities and H-1 NMR spectra of the resulting vinyl-type reactive microspheres were characteristic of microgel-like polymers.

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The emulsion polymerization of lauryl methacrylate and its copolymerization with trimethylolpropane trimethacrylate (TMPTMA) were investigated. The induction period (IP) for LMA polymerization was observed to be very long as compared to substantially no IP for methyl methacrylate polymerization. The addition of TMPTMA as a crosslinker clearly prolonged IF, owing to the reduced radical entry of oligomeric growing radical having rather hydrophilic and crosslinkable TMPTMA units into the polymer particle surface. Besides, no gelation was observed even above 90% conversion for LMA/TMPTMA(80/20) copolymerization. The initial abrupt increase in the conversion dependencies of weight-average molecular weight results from the compartmentalization of reaction loci and the gel effect. (C) 1999 Elsevier Science Ltd. All rights reserved.

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The emulsion polymerization and copolymerization of allyl methacrylate (AMA) initiated by potassium peroxodisulfate (KPS) using sodium dodecylsulfate (SDS) as an emulsifier were studied. Polymerization shows two distinct non-stationary rate regions with the maximum rate at ca. 50% conversion. The maximum rate of polymerization is found to be proportional to 0.68 and 0.25 power of KPS and SBS concentrations, while the number of particles is proportional to 0.54 and 0.67 power, respectively. The increased number of polymer particles as reactive crosslinked-polymer microspheres, the polymerization in the polymer particle surface area, the small monomer/polymer weight ratio, and the gel effect are assumed to be operative. The particle size decreased and the particle number increased with increasing the KPS and SDS concentrations. Moreover, the particle size continued to increase with conversion, up to a high conversion; this is due to the particle growth events by both agglomeration and propagation reactions, and the continued nucleation of particles to a high conversion region. The non-uniform particle morphology results from the agglomeration of microgels between themselves and with large stable particles. The polymerization accompanied by crosslinking mainly occurs in the surface area of the particles because of the restricted penetration of radicals into crosslinked particle cores. Where the T-g of the resulting polymer is much higher than the polymerization temperature, the particles become glassy during the polymerization, as is the typical case of AMA/methyl methacrylate (MMA) copolymerization; at a late stage of polymerization, the preferential polymerization in the surface area of polymer particles leads to the enhanced formation of network structure? resulting in the microgel-like polymers consisting of poly(MMA)-rich core and poly(MMA-co-AMA)-network shell. (C) 1999 Elsevier Science Ltd. All rights reserved.

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It is not possible to improve the toughness of triallyl isocyanurate (TAIC) resins by applying the procedures useful for diallyl phthalate (DAP) resins as typical allyl resins. The results obtained an discussed in connection with the network structure of TAIC resin. Thus, the polymerization of TAIC would provide a homogeneous network accompanied by the incomplete occurrence of intermolecular crosslinking reactions caused by the rigidity of polymer chains, although DAP resins would consist of the microheterogeneous networks as the agglomerate of colloidal particles.

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During our investigation concerned with the free-radical crosslinking copolymerization of benzyl methacrylate with neopentyl glycol dimethacrylate(a) in the presence of lauryl mercaptan(b) as a chain transfer agent with the intention to remove the obstacles between allyl and vinyl polymerizations, we observed, by chance, popcorn formation in spite of the presence of a large amount of chain transfer agent.

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As part of our continuing studies concerned with the elucidation of three-dimensional network formation mechanism in the free-radical crosslinking polymerization of multivinyl compounds, this article deals with the pursuit of network formation processes beyond the gel point in the copolymerization of methyl methacrylate (MMA) with ethylene dimethacrylate by ESR spectroscopy, especially focusing on the microheterogenization of network structure. Thus, poly (MMA-co-CuMAOTPP) s were prepared by the copolymerization of MMA with copper (II) methacryloyloxyphenyl tetraphenylporphyrin (CuMAOTPP) and their usefulness as polymer spin probes was examined as compared with its low-molecular-weight counterpart or copper (II) tetraphenylporphyrin (CuTPP). Poly (MMA-co-CuMAOTPP) of moderate molecular weight, i.e. about 20,000 was more useful than CuTPP for ESR spectroscopic investigation, but the polymer spin probe having 95,000 of molecular weight decreased its effectivity reversely. Then, the correlation between ESR spectra and microheterogeneity of networks formed under various polymerization conditions was examined by changing the factors influencing resultant network structures, including monomer concentration, crosslinker content and flexibility of network segments. Clearly, the mobility restriction of polymer spin probe by network formation was reduced under the conditions introducing inhomogeneous networks as a reflection of the exclusion of polymer spin probe into void part of a gelled system. Finally, the quantitative discussion on the microheterogeneity of network structure was attempted by simulating the observed ESR spectra.

DOI： 10.11364/networkpolymer1996.20.20

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As part of our continuing studies concerned with the radical polymerization of multiallyl compounds, the polymerization behavior of triallyl isocyanurate (TAIC) was compared in detail with those of its isomer triallyl cyanurate (TAC). It was found by chance that the primary chain length of the TAIC polymer obtained was quite high compared with TAC polymerization. This is ascribed to the reduced occurrence of monomer chain transfer characteristic of the polymerization of allyl compounds due to the steric effect on transition state formation by the bulky side-chain group, providing an interesting example of reaction control in radical polymerization. In order to discuss in more detail this kind of the specific polymerization behavior of TAIC, this work deals with the polymerization and copolymerization of corresponding trimethallyl compounds including trimethallyl isocyanurate (TMAIC) and trimethallyl cyanurate (TMAC) having additional allylic hydrogens as a-methyl group in which no steric hindrance may occur for the transition state formation of monomer chain transfer reaction. TMAIC showed almost no homopolymerizability, while only slightly reduced polymerizability was observed for TMAC as compared with TAG. Specificity of TAIC polymerization was almost lost by copolymerizing about 20 mol% of TAC or TMAC, (C) 1998 Elsevier Science Ltd. All rights reserved.

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Radical solution polymerization of triallyl isocyanurate was conducted in methyl benzoate or hexyl benzoate as good or poor solvent, respectively, using AIBN as initiator at 60 degrees C. An increased rate of polymerization, enlarged primary chain length, and promoted gelation were observed in the poor solvent. The actual gel point was compared with the theoretical one; the discrepancy between these points was great, although no substantial solvent effect was detected. These results are discussed in comparison with the results obtained from the polymerizations of its isomer triallyl cyanurate and diallyl terephthalate, a typical diallyl ester. The swelling ratio of the gel obtained just beyond the gel point was quite high, suggesting no microgelation up to the gel point conversion even in the solution polymerization.

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As an extension of our continuing studies concerned with the elucidation of three-dimensional network formation mechanism in the radical polymerization of multivinyl compounds, this paper deals with the post-polymerization of the precopolymers having pendant allyl groups prepared from the copolymerization of allyl methacrylate (AMA) with methyl methacrylate (MMA) or benzyl methacrylate (BzMA) as the model of prepolymer. Thus we obtained the following results : A remarkable concentration dependence was observed for the post-polymerization of poly (MMA-co-AMA) (P<SUB>w</SUB>= 2600) as a high-molecular-weight precopolymer, whereas for the low-molecular-weight poly (MMA-co-AMA) (P<SUB>w</SUB>= 100) was almost no concentration effect. Moreover, for the post-polymerization of poly (BzMA-co-AMA) (P<SUB>w</SUB>= 3400) the concentration effect was quite reduced compared with poly (MMA-co-AMA). These results are discussed as correlated to the physical interaction among polymer chains.

DOI： 10.11364/networkpolymer1996.19.65

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS INC  

Polymerizations of several diallyl alkyl isocyanurates were investigated to explore in more detail the steric effect observed in the polymerization of triallyl isocyanurate [3, 5], as compared to its isomer triallyl cyanurate, by changing alkyl groups from methyl, propyl, hexyl, and octyl up to lauryl. The rate of polymerization, the gel point, the cyclization constant, and the primary chain length were evaluated. For example, the primary chain length increased with an increase in the bulkiness of the alkyl group as expected, although in the polymerization of diallyl lauryl isocyanurate it decreased as a reflection of reduced rate of propagation due to the enhanced steric effect arising from a very bulky lauryl group.

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A novel water-soluble small band gap (below 0.5 eV) polymer containing porphyrin units in its main chain a as prepared from pyrrole, sodium o-benzaldehyde sulfonate and dipyrryletioporphyrin by addition-condensation polymerization.

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The control of network formation is discussed as an extension of our studies concerned with the network formation mechanism in the free-radical polymerization and copolymerization of multivinyl compounds. The guideline of the control of network formation is as follows: the key reaction for the control of gelation is the intermolecular crosslinking leading to the formation of crosslinked polymer, while the key reaction for the control of network structure is the intramolecular crosslinking leading to the formation of multiple crosslinkages generating the network structure of crosslinked polymer. Thus the control of the intermolecular and intramolecular crosslinking reactions is discussed in terms of the steric effect of long-chain alkyl groups on the gelation and microgelation in alkyl methacrylate/ethylene dimethacrylate or trimethylolpropanetrimethacrylate copolymerizations and the polar effect of the nonpolar main chain-polar side chains and the polar main chain-nonpolar side chains types systems on the gelation of their copolymerizations, respectively.

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In the emulsion polymerization of allyl methacrylate (AMA), no gelation occurred, whereas gelation occurred easily at about 4% conversion in the bulk polymerization. Thus, the reactive cross-linked-polymer microspheres as microgel-like polymers with abundant pendant allyl groups were easily obtained in the emulsion polymerization because AMA possesses two types of vinyl groups, methacrylic and allylic double bonds, having greatly different reactivities. The weight-average molecular weights, the r.m.s. radii of gyration, the second virial coefficients, the intrinsic viscosities, and H-1-NMR spectra of the resulting allyl-type reactive microspheres were characteristic of microgel-like polymers as compared with those of the branched-polymer-like prepolymers obtained in bulk. The precopolymers prepared from the emulsion copolymerization of AMA with methyl methacrylate and ethylene dimethacrylate in order to obtain the crosslinked-polymer microspheres having different crosslinking densities were also characterized, although the results obtained are not in conformity with our expectation.

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Zinc(II) tetraphenylporphyrin (ZnTPP) moieties are covalently attached to amphiphilic sodium polysulfonates carrying about 60 mol % of lauryl (LA), 2-(naphthyl)methyl (Naph), or cyclododecyl (CD) groups. The ZnTPP moieties are compartmentalized within the hydrophobic clusters in aqueous solution, The charge transfer complexation of the compartmentalized ZnTPP moieties with methylviologen (MV2+) is completely suppressed, The electron transfer (ET) from the singlet excited state of the ZnTPP chromophore to MV2+ in the compartmentalized system is 2 orders of magnitude Blower than that in a reference copolymer system having no hydrophobic groups. The apparent second-order rate constants for the ET from the triplet, excited state of the ZnTPP chromophore to MV2+ are almost equal in all the polymer systems. The accumulation of ZnTPP+. was observed as a result of the compartmentalization. The Naph and CD groups are more effective in the accumulation of ZnTPP+. than is the LA group. ZnTPP+. persisted over st period of milliseconds in the terpolymer systems containing the Naph and CD groups.

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As part of our continuing studies is concerned with the free-radical crosslinking polymerization of multivinyl compounds, this article deals with the inhomogeneity of network structure accompanied by the radical accumulation which can be detected by electron spin resonance (ESR) method, in the radical polymerization of multiallyl compounds. Pendant allyl radicals were detected in the bulk polymerizations of triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), diallyl phthalate (DAP), diallyl isophthalate (DAI), diallyl terephthalate (DAT), and triallyl trimellitate (TAT). The pendant allyl radical easily reacted with oxygen, while no reaction was observed with 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine-1 -oxyl (TEMPOL) as a bulky molecule. This kind of steric effect is ascribed to the inhomogeneity of network structure; thus the pendant allyl radicals belong to the densely crosslinked part. Conversion dependence of the pendant allyl radical accumulation was different for each polymerization; this reflects the difference of the network formation processes, especially including the occurrence of intramolecular crosslinking.

DOI： 10.11364/networkpolymer1996.18.1

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Water-soluble polymers were prepared from pyrrole and sodium o-benzaldehydesulfonate by addition-condensation polymerization, The bandgap of the polymer obtained was estimated to be less than 0.5 eV.

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Amphiphilic terpolymers [consisting of ca. 40 mol % sodium sulfonate group, ca. 60 mol % lauryl(La) or cyclododecyl(Cd) group, and 0.1-0.2 mol % zinc(II) tetraphenylporphyrin (ZnTPP) moiety] form unimer micelles in aqueous solution, and the ZnTPP moieties are compartmentalized in the hydrophobic microdomains in the unimer micelles, leading to an extraordinarily long-lived triplet excited state of the ZnTPP((ZnTPP)-Zn-3*). Electron transfer from the long-lived (ZnTPP)-Zn-3* to phenylmethylphenacylsulfonium p-toluenesulfonate (PMPS), a self-destructive electron acceptor, which is electrostatically concentrated on the surface of the unimer micelle, generates porphyrin cation radicals (ZnTPP.+) within the hydrophobic microdomain. Since the ZnTPP chromophores are protected from the bulk aqueous phase, subsequent reaction between the resulting ZnTPP.+ and phenacyl radical from PIMPS is prevented. Thus, the porphyrin cation radicals are efficiently accumulated under steady-state irradiation of visible light. The unimer micelle consisting of Cd groups provides a much better protection for ZnTPP.+ than that consisting of La groups; a significant amount of the porphyrin cation radical persisted for more than 1 day in the unimer micelle consisting of the Cd groups.

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The critical conditions in which the classical Flory-Stockmayer gelation theory (F-S theory) is applicable to monovinyl-divinyl copolymerizations were pursued in detail. The resulting prepolymers or precursors of ideal crosslinked-polymers were characterized as standard polymers for the discussion of network formation in free-radical monovinyl-divinyl copolymerizations. Methyl methacrylate was copolymerized with a small amount of ethylene dimethacrylate, butylene dimethacrylate or nonapropyleneglycol dimethacrylate in the presence of lauryl mercaptan, a chain transfer agent to reduce the occurrence of a thermodynamic excluded volume effect and intramolecular crosslinking as the primary and secondary factors, respectively, for the greatly delayed gelation in the free-radical monovinyl-divinyl copolymerizations and, moreover, to keep the primary chain length constant by inhibiting a gel effect. The ratio of the actual gel point to the theoretical one reached 1.1, supporting the validity of F-S theory. The resulting prepolymers were subjected to SEC-MALLS analysis to determine the molecular weights, the molecular-weight distributions and the radii of gyration; the correlations of molecular weight vs. elution volume and radius of gyration vs. molecular weight were useful for the characterization of the precursors of ideal network-polymers.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

The microheterogeneous network formation processes in the free-radical copolymerization of methyl methacrylate (MMA) with ethylene dimethacrylate (EDMA) were pursued Electron spin resonance (ESR)-spectroscopically by using copper tetraphenylporphyrin (CuTPP) and copper methacryloyloxyphenyl triphenylporphyrin (CuMAOTPP) as spin probes. Thus, CuTPP could be a useful tool to evaluate the mobility of low-molecular-weight molecules in the gelled system. In the MMA-EDMA copolymerization containing CuMAOTPP, three types of CuTPP moieties existed in the polymerization solution as immobilized in the densely crosslinked network, incorporated into the loosely crosslinked network, and unreacted monomer; their proportion was estimated by a semi-quantitative spectral simulation. For example, in the MMA-EDMA (70:30)-CuMAOTPP terpolymerization in a dilution of 1/10 in benzene, 30% of CuMAOTPP was immobilized at 76% conversion by the densely crosslinked network or microgel, just like as in a frozen state, while no restricted mobility was observed for unreacted CuMAOTPP in spite of a complete loss of fluidity of the polymerization solution.

Web of Science

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Language：Japanese   Publisher：Japan Thermosetting Plastics Industry Association  

As part of our continuing studies concerned with the free-radical crosslinking polymerization of multivinyl compounds, this article deals with the preparation of crosslinked polymer microspheres by the emulsion polymerization of allyl methacrylate (AMA); the resulting microspheres as pseudo-microgels were characterized and post-polymerized. Firstly, the solution polymerization behavior of AMA was pursued by light scattering in comparison with the polymerization of ethylene dimethacrylate in which microgelation occurs easily ; thus no microgelation was observed up to the gel-point conversion as a reflection of the low reactivity of growing methacrylyl radical toward the pendant allyl groups of prepolymer resulting in the suppressed occurrence of intramolecular crosslinking. Secondly, the emulsion polymerization of AMA was compared with the bulk polymerization ; no gelation was observed even above 90% conversion, while in the bulk polymerization the gel point was determined as 4%. The resulting polymers were then characterized by examining the conversion dependences of weight-average molecular weight and molecular-weight distribution, the correlations of molecular weight vs elution volume and r. m. s. radius of gyration vs molecular weight, the intrinsic viscosity, <SUP>1</SUP>H-NMR spectrum, and the conversion dependence of residual allyl group, thus suggesting that the microgel-like polymers of low crosslinking density could be obtained by the emulsion polymerization. Finally, these reactive crosslinked polymer microspheres of abundant pendant allyl groups were post-polymerized as comared with the post-polymerization of an ordinary prepolymer : The rates of polymerization and gel formation were low in the post-polymerization of microsphere and they became remarkable with increasing microshere size. The swelling ratio of resulting gel was quite small even at an early stage of polymerization and its conversion dependence showed a minimum point. In addition, the post-polymerization behavior of microsphere depended markedly on concentration. These are discussed, considering the concurrent occurrence of intramolecular and intermolecular crosslinking, and the entanglement of polymer chains.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Polymers containing porphyrins were synthesized from pyrrole, 1-dodecanal, and (2-formyl-5,10,15,20-tetraphenylporphyrinato)oxovanadium(IV) or 2,8,12,18-tetraethyl-3,7,13,17-tetramethyl-5,10-dipyrrylporphine. The number-average molecular weights of the resulting polymers were about 3000. NMR and absorption spectral data show the formation of the pi-conjugated polymer.

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Language：Japanese   Publisher：Japan Thermosetting Plastics Industry Association  

As part of our continuing studies concerned with the elucidation of reaction mechanism and the control of the network formation in the radical monovinyl-divinyl copolymerizations, this article deals with the radical copolymerizations of tert-butyl methacrylate (tBMA) with various polyethylene glycol dimethacrylates [CH<SUB>2</SUB>=C (CH<SUB>3</SUB>) CO (OCH<SUB>2</SUB>CH<SUB>2</SUB>) <SUB>n</SUB>OCOC (CH<SUB>3</SUB>) =CH<SUB>2</SUB> (n= 1, 2, 3, 4, 9, and 23) (PEGDMA); the effect of bulky tert-butyl groups on the three-dimensional network formation processes was examined in detail by comparing with our previous results of methyl methacrylate (MMA) - PEGDMA copolymerizations. Thus, in MMA - PEGDMA copolymerization systems, the primary chain length of the resulting prepolymers increased significantly with an increase in the oxyethylene unit number, n, of PEGDMA<SUP>7) </SUP>, while the primary chain length dependency on n was quite small in tBMA-systems as the highest value was only 1.8 times of the one obtained at n=1. Actual gel points were observed at higher conversions in tBMA-PEGDMA copolymerizations ; apparently, gelation was delayed. The deviation of actual gel point from theoretical one became greater in tBMA-systems. The remarkably enhanced deviation with an increase in n was observed in MMA-systems, while the tBMA-systems showed a reversed tendency as was a bit reduced deviation. These results are ascribed to a suppressed occurrence of intramolecular cyclization accompanied by the loop structure formation<SUP>7) </SUP>, intermolecular crosslinking, and intramolecular crosslinking as a reflection of a lessened flexibility of polymer main chain and a steric effect due to the bulky tert-butyl groups. Some supporting evidences are obtained from the correlation curve between molecular weight and elution volume and the conversion dependence of molecular weight distribution curves determined by SEC-MALLS, and also the correlations of both r.m.s. radius of gyration and second virial coefficient with molecular weight by light scattering measurements.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC PHOTOBIOLOGY  

Small mole fractions of zinc(II) tetraphenylporphyrin (ZnTPP) moieties were covalently incorporated into amphiphilic polysulfonates having bulky hydrophobic groups such as lauryl, cyclododecyl, and (2-naphthyl)methyl (Np) groups in their side chains. The ZnTPP moieties are ''compartmentalized'' in the hydrophobic domains of these amphiphilic polyelectrolytes in aqueous solution. For comparison, the ZnTPP moieties were covalently incorporated into a polysulfonate without hydrophobic groups. The ZnTPP moieties in this reference polymer are exposed to water in aqueous solution. The compartmentalized ZnTPP systems in aqueous fluid solution emitted phosphorescence and thermally activated delayed fluorescence at room temperature. This is due to an extremely long-lived triplet excited state in the compartmentalized systems at room temperature in aqueous solution, e.g. 19 ms for ZnTPP compartmentalized in Np domains, compared with 3 ms for ZnTPP in the reference polymer. These remarkable compartmentalization effects may be attributed to a restriction of motional freedom of the ZnTPP moiety isolated in a rigid and hydrophobic microenvironment provided by the amphiphilic polyelectrolytes in aqueous solution.

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

The temperature dependence of the magnetic susceptibilities for 4-methacryloyloxy- and 4-acryloyloxy-2,2,6,6-tetramethylpiperidin-1-oxyl (MOTMP and AOTMP, respectively) was measured. Intermolecular magnetic coupling in these radicals was changed from antiferromagnetic to ferromagnetic by substituting hydrogen at alpha-position with a methyl group. A magnetic phase transition for MOTMP was observed at 0.14 K in the measurement of the temperature dependence of heat capacity. The circumstantial evidences support that the ordered state is of ferromagnet.

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Web of Science

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Event date： 2018.9

Venue：名古屋国際会議場  

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Event date： 2018.9

Venue：筑波大学  

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Event date： 2018.9

Venue：筑波大学  

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Event date： 2018.9

Venue：名古屋国際会議場  

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Event date： 2018.9

Venue：名古屋国際会議場  

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Event date： 2018.9

Venue：筑波大学  

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Event date： 2018.9

Venue：筑波大学  

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Event date： 2018.9

Venue：名古屋国際会議場  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：北海道大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.9

Venue：関西学院大学  

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Event date： 2018.7

Venue：神戸  

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Event date： 2018.7

Venue：神戸  

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Event date： 2018.7

Venue：神戸  

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Event date： 2018.7

Venue：神戸  

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Event date： 2018.7

Venue：神戸  

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Event date： 2018.7

Venue：神戸  

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Event date： 2018.5

Venue：名古屋  

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Event date： 2018.5

Venue：名古屋  

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Event date： 2018.5

Venue：名古屋  

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Event date： 2018.5

Venue：名古屋  

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Event date： 2018.5

Venue：名古屋  

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Event date： 2018.5

Venue：名古屋  

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Event date： 2018.5

Venue：名古屋  

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Event date： 2018.5

Venue：名古屋  

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Event date： 2018.5

Venue：名古屋  

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Event date： 2018.5

Venue：名古屋  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：松山  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：仙台  

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Event date： 2017.9

Venue：神戸  

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Event date： 2017.9

Venue：神戸  

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Event date： 2017.9

Venue：神戸  

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Event date： 2017.9

Venue：神戸  

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Event date： 2017.9

Venue：神戸  

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Event date： 2017.7

Venue：神戸  

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Event date： 2017.7

Venue：神戸  

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Event date： 2017.7

Venue：神戸  

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Event date： 2017.7

Venue：神戸  

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Event date： 2017.7

Venue：神戸  

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Event date： 2017.7

Venue：神戸  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.5

Venue：幕張メッセ  

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Event date： 2017.3

Venue：慶應義塾大学  

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Event date： 2017.3

Venue：慶應義塾大学  

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Event date： 2017.3

Venue：慶應義塾大学  

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Event date： 2016.9

Venue：横浜  

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Event date： 2016.9

Venue：横浜  

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Event date： 2016.9

Venue：横浜  

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Event date： 2016.9

Venue：横浜  

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Event date： 2016.9

Venue：横浜  

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Event date： 2016.9

Venue：横浜  

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Event date： 2016.9

Venue：横浜  

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Event date： 2016.9

Venue：横浜  

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Event date： 2016.9

Venue：横浜  

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Event date： 2016.9

Venue：東京  

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Event date： 2016.9

Venue：東京  

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Event date： 2016.9

Venue：東京  

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Event date： 2016.9

Venue：東京  

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Event date： 2016.9

Venue：東京  

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Event date： 2016.9

Venue：東京  

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Event date： 2016.9

Venue：東京  

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Event date： 2016.9

Venue：東京  

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Event date： 2016.7

Venue：神戸  

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Event date： 2016.7

Venue：神戸  

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Event date： 2016.7

Venue：神戸  

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Event date： 2016.5

Venue：神戸  

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Event date： 2016.5

Venue：神戸  

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Event date： 2016.5

Venue：神戸  

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Event date： 2016.5

Venue：神戸  

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Event date： 2016.5

Venue：神戸  

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Event date： 2016.5

Venue：神戸  

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Event date： 2016.5

Venue：神戸  

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Event date： 2016.5

Venue：神戸  

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Event date： 2015.12

Venue：USA（Hawaii）  

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Event date： 2015.12

Venue：USA（Hawaii）  

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Event date： 2015.12

Venue：USA（Hawaii）  

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Event date： 2015.9

Venue：仙台  

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Event date： 2015.9

Venue：仙台  

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Event date： 2015.9

Venue：仙台  

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Event date： 2015.9

Venue：仙台  

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Event date： 2015.9

Venue：仙台  

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Event date： 2015.9

Venue：仙台  

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Event date： 2015.9

Venue：仙台  

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Event date： 2015.9

Venue：大阪  

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Event date： 2015.9

Venue：大阪  

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Event date： 2015.9

Venue：大阪  

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Event date： 2015.9

Venue：大阪  

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Event date： 2015.9

Venue：大阪  

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Event date： 2015.9

Venue：大阪  

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Event date： 2015.9

Venue：大阪  

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Event date： 2015.5

Venue：札幌  

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Event date： 2015.5

Venue：札幌  

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Event date： 2015.5

Venue：札幌  

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Event date： 2015.2

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Event date： 2015.1

Venue：岡崎  

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Event date： 2014.11

Venue：吹田  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.10

Venue：札幌  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：長崎  

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Event date： 2014.9

Venue：札幌  

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Event date： 2014.8

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Event date： 2014.7

Venue：神戸  

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Event date： 2014.5

Venue：名古屋  

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Event date： 2014.5

Venue：名古屋  

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Event date： 2014.5

Venue：名古屋  

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Event date： 2014.5

Venue：名古屋  

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Event date： 2014.5

Venue：名古屋  

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Event date： 2014.5

Venue：名古屋  

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Event date： 2014.5

Venue：名古屋  

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Event date： 2014.3

Venue：青山学院大学相模原キャンパス  

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Event date： 2013.12

Venue：横浜市開港記念会館  

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Event date： 2013.9

Venue：Doshisha Kyoto  

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Event date： 2013.9

Venue：同志社大学田辺キャンパス  

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Event date： 2013.9

Venue：愛媛大学 松山  

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Event date： 2013.9

Venue：金沢大学  

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Event date： 2013.9

Venue：愛媛大学 松山  

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Event date： 2013.9

Venue：愛媛大学 松山  

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Event date： 2013.9

Venue：愛媛大学 松山  

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Event date： 2013.9

Venue：金沢大学  

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Event date： 2013.9

Venue：The Univ. Club at Queen's, Kingston, Ontario, Canada  

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Event date： 2013.9

Venue：台湾国立精華大学, Hsinchu, Taiwan  

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Event date： 2013.9

Venue：台湾国立精華大学, Hsinchu, Taiwan  

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Event date： 2013.8

Venue：Kobe Convention Center  

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Event date： 2013.7

Venue：兵庫県民会館  

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Event date： 2013.6

Venue：日本科学未来館 東京  

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Event date： 2013.6

Venue：Kanazawa 石川音楽堂  

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Event date： 2013.5

Venue：京都国際会館  

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Event date： 2013.5

Venue：京都国際会館  

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Event date： 2013.5

Venue：京都国際会館  

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Event date： 2013.3

Venue：神奈川工科大学  

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Event date： 2013.3

Venue：福岡国際会議場  

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Event date： 2013.3

Venue：福岡国際会議場  

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Event date： 2013.1

Venue：金沢  

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Event date： 2012.12

Venue：(神戸国際会議場)  

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Event date： 2012.12

Venue：(沖縄産業支援センター )  

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Event date： 2012.11

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Event date： 2012.10

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Event date： 2012.10

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Event date： 2012.9

Venue：京都  

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Event date： 2012.9

Venue：名古屋（名古屋工業大学）  

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Event date： 2012.9

Venue：名古屋（名古屋工業大学）  

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Event date： 2012.9

Venue：名古屋（名古屋工業大学）  

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Event date： 2012.9

Venue：名古屋（名古屋工業大学）  

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Event date： 2012.9

Venue：名古屋（名古屋工業大学）  

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Event date： 2012.9

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Event date： 2012.9

Venue：東京（東京工業大学）  

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Event date： 2012.9

Venue：東京（東京工業大学）  

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Event date： 2012.9

Venue：東京（東京工業大学）  

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Event date： 2012.9

Venue：東京（東京工業大学）  

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Event date： 2012.9

Venue：東京（東京工業大学）  

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Event date： 2012.9

Venue：東京（東京工業大学）  

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Event date： 2012.9

Venue：東京（東京工業大学）  

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Event date： 2012.9

Venue：松山（愛媛大学・松山大学）  

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Event date： 2012.9

Venue：松山（愛媛大学・松山大学）  

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Event date： 2012.6

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Event date： 2012.6

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Event date： 2012.6

Venue：東京（未来科学館）  

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Event date： 2012.5

Venue：横浜（パシフィコ横浜）  

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Event date： 2012.5

Venue：横浜（パシフィコ横浜）  

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Event date： 2012.5

Venue：横浜（パシフィコ横浜）  

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Event date： 2012.5

Venue：横浜（パシフィコ横浜）  

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