1999 Fiscal Year Final Research Report Summary
Structure and Dynamics of Network Janctions in Thermoreversible Gels of Associating Polymers
| Project/Area Number |
09650987
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
高分子構造・物性(含繊維)
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
TANAKA Fumihiko Kyoto University, Dep Pdymer Chemistry, Professor, 工学研究科, 教授 (50107695)
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| Co-Investigator(Kenkyū-buntansha) |
田中 文彦 京都大学, 工学研究科, 教授 (50107695)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Associating Polymers / Thermoreversible Gels / Multiplicity of Cross-links / Hydrophobic Aggregation / Intramolecular Micelle / Helix-Coil Transition / Network Structure / Monte Carlo Simulation |
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| Research Abstract |
This project studied thremoreversible gelation of associating polymers with multiple cross-link junctions. We paid special attention to (1) the multiplicity and sequence length of the network junctions, (2) motion of network junctions and the number of elastically effective chains, (3) competition between intermolecular micellization and intermolecular cross-linking, (4) effect of added surfactants, (5) cooperative effect of conformational change of polymers and gelation, (6) formation of mixed networks. We derived complete phase diagrams including phase separation, gelation, micellization, microphase separation etc. The conventional Eldridge-Ferry method is extended to evaluate multiplicity, as well as enthalpy, of the cross-links, and applied to the experimental gel melting curves of poly (vinyl alcohol) in water. The effect of added surfactants on the formation of reversible gels in hydrophobically modified polymer solutions is also studied under the assumption of the existence of a minimum multiplicity required for stable cross-links. For telechelic associating polymers, we found the condition for appearance of flower micelles (micelles formed only by loops) before the gel point.
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