| Co-Investigator(Kenkyū-buntansha) |
WU W.L. アメリカ合衆国国立標準局, 高分子部門, 研究員
HAN C.C. アメリカ合衆国国立標準局, 高分子部門, 班長
MUTHUKUMAR M. University of Massachusetts at Amherst, 高分子研究所, 教授
STEIN R.S. マサチューセッツ大学, 高分子研究所, 所長
トランコン クイー 京都工芸繊維大学, 繊維学部, 助手 (50188827)
YANO Okimichi Kyoto Institute of Technology, 繊維学部, 助教授 (00010942)
SHIBAYAMA Mitsuhiro Kyoto Institute of Technology, 繊維学部, 助教授 (00175390)
WU Wen-li National Institute of Standards and Technology
HAN Charles C. National Institute of Standards and Technology
TRAN-CONG Qui Kyoto Institute of Technology
STEIN Richard S. University of Massachusetts at Amherst
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| Research Abstract |
Structure, solgel transition behavior, and dynamic aspects of polymer gels were investigated in terms of small angle neutron scattering (SANS), viscometry, forced Rayleigh scattering (FRS), fluorescence depolarization methods, and ultrasonic spectrosopy. Topological features of polymer gels were also studied by generating bimodal networks.
SANS of poly (vinyl alcohol) (PVA) solutions
The correlation length, xi, was estimated from a generalized Zimm plot for fractals having the fractal dimension of D. The variation of xi with temperature showed a gel-to-sol transition. The scattered intensity functions for the gels at different temperatures could be superimposed by employing reduced variables, I(q)/Cxi^3 and xiq, where C and q are the monomer concentration and the magnitude of the scattering vector, respectively.
Phase behavior and solgel transition of PVA-borate complex in aqueous solutions
At a given combination of PVA concentration and ionic strength, the system underwent a clear-opaque-
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clear transition with increasing boric acid concentration. This behavior was explained by a balance of the exclude volume effect due to intra- and inter-chain crosslinks and electrostatic potentials.
Dynamical aspects of thermoreversible gelation of polymer solutions
Solutions of poly (n-butyl methacrylate) (PnBNA), poly (isobutyl methacrylate) (PiBMA), poly (tert-butyl methacrylate) (PtBMA) and poly (2-hydroxyethyl methacrylate) (PHEMA) in 2-propanol and 2-butanol were used as samples. The thermoreversible gelation mechanism of poly (butyl methacrylate)/2-propanol solutions strongly depends on the chemical structures of their isomers. It was also found that the elastic energy that is generated by the chemical gelation of polystyrene (PS) chains in a binary mixture of PS and poly (2-chlorostyrene) (P2CS), modifies the concentration fluctuations of PS/P2CS mixtures.
Bimodal Polymer Networks
Computer simulations were performed on two and three dimensional square lattices with tetrafunctional crosslinks. The simulated networks demonstrated the presence of appreaciable of number of network imperfections, such as unsatisfied crosslinks (chain extenders), isolated chains, unreacted crosslink agents, and dangling chains. It was found that the simulated chains re-produced several topological features of real elastomers. Less
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