Swelling and Stress Relaxation of Stretched Gels near the Volume Phase Transition Point
| Project/Area Number |
08651076
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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 |
TAKIGAWA Toshikazu Kyoto University, Department of Material Chemistry, Associate Professor, 工学研究科, 助教授 (50201603)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Polymer Gel / Volume Phase Transition / Uniaxial Elongation / Swelling / Stress Relaxation / Diffusion / ゲル |
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| Research Abstract |
Swelling and mechanical properties were investigated for poly (acrylamide)(PAAm) and poly (N-isopropylacrylamide)(PNIPA) gels. The degree of swelling and equilibrium stress values under uniaxial deformation were measured for PAAm gels and were compared with those from the theoretical prediction. The values obtained from the experiment agreed fairly well with the theoretical prediction. Deswelling kinetics of PNIPA gels measured by a temperature (T) jump across the volume phase transition temperature showed that the relaxation time for the volume change is of the same order of magnitude of the vanishing time of the heterogeneous region inside the gels at long times. The relaxation time decreased with increasing final temperature of the T-jump. Initial Young's modulus (E_0) of PNIPA gels were measured both in swollen and collapsed states, and the concentration dependence of E_0 was investigated. The value of E_0 in the collapsed state was much higher than that estimated using the values in the swollen state, suggesting that the number of crosslinks increased at the volume phase transition from swollen to collapsed states. The crosslinks were considered to be a sequence of hydrogen bonds between the polymer chains.
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Report
(3 results)
Research Products
(10 results)
