2003 Fiscal Year Final Research Report Summary
Elucidation of Static and Dynamic Properties of Highly Branched Polymers
| Project/Area Number |
14550844
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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 | Kanazawa University |
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Principal Investigator |
YAMAGISHI Tada-aki Kanazawa University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (90220251)
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| Co-Investigator(Kenkyū-buntansha) |
INONE Tadashi Kyoto University, Institute for Chemical Research, Associate Professor, 化学研究所, 助教授 (80201937)
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| Project Period (FY) |
2002 – 2003
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| Keywords | Phenolic resin / Highly branched polymer / Dilute solution properties / Conformation / Methylene linkage pattern / Dynamic birefringence measurement / Stress optical coefficient / Segment orientation mechanism |
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| Research Abstract |
Highly branched polymer was prepared by the condensation of phenol with paraformaldehyde in acetic acid using HC1 as catalyst. Linear polymer was prepared by the condensation of o-cresol with paraformaldehyde in acetic acid using HC1 as catalyst. The molecular weight dependence of intrinsic viscosity [η] and mean-square radius of gyration <S^2> for the highly branched and linear polymers were determined and the effect of side chain on the molecular conformation in solution was elucidated, respectively. For the linear polymer with lauroyl group, the phenolic main chain was aggregated in the center of molecule and the alkyl side chain was external to the molecule in n-octane. The conformation was like a micelle. On the other hand, the phenolic main and alkyl side chain coexisted and the conformation was extended in MIBK. For the highly branched polymer the effect of side chain on the conformation is not remarkable. This is due to the flexibility of linear polymer.
A graft copolymer having
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poly(2-vinylpyridine) trunk and sixty-eight polystyrene branches was prepared by anionic coupling method. The trunk span between branching points was about two times wider than the Rouse segment size for linear polystyrene. Dynamic birefringence and dynamic viscoelastic measurements around Tg zone showed that the complex Young's modulus and the strain optical coefficient of the copolymer was similar to those of linear polystyrene. The stress optical coefficients for the rubbery and the glassy components, respectively, agreed with those for linear polystyrene, meaning that no indication of microphase separation was ideologically detected over a whole rang of frequencies studied. The effect of branching was not observed in the frequency dependence of the glassy component. In the rubbery zone, the mode observed at short times was attributed to motion of polystyrene branches, and the other mode at long times was related to the motion of poly(2-vinylpyridine) trunk. Although Mw of poly(2-vinylpyridine) was much higher than the molecular weight of entanglement strands of linear polystyrene, the rubbery plateau zone was not clearly observed, possibly due to inhibition ofentanglements by branching. Less
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Research Products
(8 results)
