1998 Fiscal Year Final Research Report Summary
Structure Changes of Polymeric Materials under Large Deformation
| Project/Area Number |
09450361
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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 |
OSAKI Kunihiro KYOTO UNIVERSITY,Institute for Chemical Research, Professor, 化学研究所, 教授 (00027046)
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| Co-Investigator(Kenkyū-buntansha) |
INOUE Tadashi KYOTO UNIVERSITY,Institute for Chemical Research, Instructor, 化学研究所, 助手 (80201937)
WATANABE Hiroshi KYOTO UNIVERSITY,Institute for Chemical Research, Associate Professor, 化学研究所, 助教授 (90167164)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Glass Transition / Viscoelasticity / Poisson Ratio / Polymeric Material |
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| Research Abstract |
Time evolution of Poisson ratio of polystyrene during elongation deformation with constant rates was measured by a newly developed tensile tester equipped with a strain gage based on LASER speckle method in order to study cohesive structure changes induced by deformation around the glass transition zone. Time evolution of the ratio measured at low strain rates, at which viscosity growth function showed linear response, could be superimposed to a composite curve by the method of reduced variables with the same shift factor for the viscoelastic function. The obtained composite curve changed from 0.33 in the glassy zone to 0.5 in the rubbery zone. However, the experimental curve was not in accord with the prediction by a simple linear response theory. This result may be attributed to strong nonlinear nature of volume relaxation phenomena. At higher strain rates, where viscosity growth function showed nonlinear response, Poisson ratio in the short time region increased.
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