1991 Fiscal Year Final Research Report Summary
Studies on Molecular Motion of Oriented Polymer Chains by the Fluorescence Analysis
| Project/Area Number |
62470094
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
高分子物性
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| Research Institution | Kyoto University |
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Principal Investigator |
YAMAMOTO Masahide Kyoto University, Polym. Chem., 工学部, 教授 (40025961)
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| Co-Investigator(Kenkyū-buntansha) |
ITO Shinzaburo Kyoto Univ., Polym. Chem. Instructor, 工学部, 助手 (50127049)
ONOGI Yoshihiko Kyoto Univ., Polym. Chem. Instructor, 工学部, 助手 (70026201)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Fluorescence Characteristics / Fluorescence Depolarization Method / Molecular Motion / Local Motion / Relaxation Times of Molecular Motions / Polymer Chain / Polymer Dilute Solution / Stereocomplex |
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| Research Abstract |
Dynamic behavior of polymer chains under various conditions was investigated by the fluorescence analysis such as time-resolved fluorescence decay (FD), time-resolved fluorescence polarization (FP) method, where fluorescent probes were attached to polymer chains.
1. Studies of local motion of polymer chains in dilute solution by FP method We prepared various polymers, e. g., polystyrene (PS), poly (methyl methacrylate) (PMMA) having anthracene probe attached just in the middle of polymer chains and measured the auto-correlation times of bond vectors of polymer chains in sub-ns and ns regions. From the results we could evaluated the dynamic chain stiffness and the coupling range of motional correlation of polymer chains. As for the solvent effect for PS chain, we found that the relaxation time of local motion in the theta solvent is longer than that in good solvents accompanying larger activation energies of local motion. We found that the relaxation time of chain ends is ca. two times faster than that of the middle part of the chain.
2. Studies of PMMA chain in semi-concentrated polymer solution by FP method We found that the relaxation times increase with the increase of polymer concentrations, but the motional modes scarcely change with the polymer concentrations. The behavior was well explained by the free volume theory.
3. 'Evaluation of torsional rigidity of PMMA stereocomplpx by PF method We found that the stereocomplex has very high torsional constant compared with the single chain.
4. Studies of conformational change of enzymes by the time-resolved FD analysis For immunoglobulin and tryptophanase, the relations between enzymatic activities and conformational changes were elucidated.
5. Molecular motion of polymer chains under shear stress by FP method We could observe the systematic change, but so far we could not correct the effect of birefringence due to polymer flow. So this problem was left unsolved for a future project.
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