1998 Fiscal Year Final Research Report Summary
Structures and Dynamics of Polymer Hybrid Chains Studied by the Fluorescence Depolarization Method
| Project/Area Number |
09450359
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 |
OHOKA Masataka KYOTO UNIVERSITY,Dept.of Polymer Chemistry, Technical Official, 工学研究科, 教務職員 (10160425)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Masahide KYOTO UNIVERSITY,Dept.of Polymer Chemistry, Emeritus Professor, 工学研究科, 名誉教授 (40025961)
ITO Shinzaburo KYOTO UNIVERSITY,Dept.of Polymer Chemistry, Associate Professor, 工学研究科, 助教授 (50127049)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Fluorescence depolarization method / Dynamic properties of polymer chains / Nanosecond time region / Local motion / Relaxation time / Thermosensitive polymer / Molecular dynamics simulation / Fluorescence probe |
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| Research Abstract |
1. Relationship between relaxation times of local motion and chemical structures for polymer chains. (1) Study of local chain dynamics for various polymer chains revealed that the local motion is strongly influenced by their chemical structures such as bulkiness of side groups, stereoregularity. (2) The relaxation time of local motion of chain ends is one tenth of that of the center for polystyrene (PS) chain. The MW dependence of relaxation times shows that rotational potential of each bond determines the relaxation times and that the largest scale of local motion is less than 200 bonds for PS.(3) The relaxation time of the chain center depends on the chain structure adjacent to a fluorescent probe for PS chain. (4) The MD simulation of polymer chain end well reproduced the observed MW dependence of the relaxation time of local motion and it showed that the local motion reflects a cooperative rotational motion of chain segments. 2. Molecular motion of polymer chain in the monolayer made of poly(alkyl methacrylate)s at air/water interface. The local motion is governed by steric hindrance of alpha-methyl group of the main chain and adjacent interaction of side groups. 3. Local motion of crosslinking points in polymer gel. The fluorescent probe which acts as a crosslinking point for poly(methyl methacrylate) gel showed that the local motion of the crosslinking point depends on the swelling ratio of polymer gel, not on the MW between the crosslinking points. 4. Local motion of polymer chain in the vicinity of a phase separation temperature for LOST system. For poly(ethoxyethyl vinylether) in which a fluorescent probe anthracene is attached in the main chain, we observed that extraordinarily enhanced fluorescence quenching took place at ca. 4。C below the LOST : 20。C.We verified the mechanism that below the LOST a dynamic quenching takes place through the collision of the fluorescent probe with fluctuating polymer segments which are fluorescence quenchers.
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Research Products
(18 results)
