1989 Fiscal Year Final Research Report Summary
Molecular motion and material properties of cosoluble polymer blends
| Project/Area Number |
63470091
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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 |
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) |
NEMOTO Norio Kyoto University, Institute for Chemical Research, Associate Professor, 化学研究所, 助教授 (90027053)
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| Project Period (FY) |
1988 – 1989
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| Keywords | polymer blend / cosoluble polymer / viscoelasticity / birefringence / stress relaxation / entanglement |
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| Research Abstract |
The blend of cosoluble polymers, polystyrene (PS) and poly(vinyl methyl ether), (PVME), was instantaneously deformed and the relaxation of stress and birefringence were measured. Owing to the difference of the segmental optical anisotropy of two polymers, one can estimate the degree of deformation of the segments of each component from the birefringence.
In the case of the blend of long PS chains and short PVME chains, the relaxation modulus exhibited two rubbery plateau regions. One, at short times and with a higher modulus was corporated with the deformation of both polymer components: the stress in this region was supported by all the polymer segments in the system. A part of the modulus then relaxed as the short PVME chains lost the effect of deformation and became optically isotropic.
The stress in the second plateau region was supported exclusively by the long PS chains and the modulus was equal to that of the PS solution, with the same PS content as the blend, in an ordinary solvent of low molecular weight.
The PS chains in the blend supported;more stress at short times than the chains in the solution did. The extra stress, apparently due to the PS-PVME entanglement, relaxed as the PVME lost the effect of deformation. The rate of relaxation was not affected by the molecular weight of the long PS chains. These results substantiate the modern concept of the polymer chain entanglement.
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