1987 Fiscal Year Final Research Report Summary
Microstructure and Molecular Dynamics of Amorphous Piezoelectric Polymers and Molecular Origin of Their Piezoelectricity
| Project/Area Number |
61470099
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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 | Tokyo Institute of Technology, Faculty of Engineering |
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Principal Investigator |
INOUE Yoshio Tokyo Institute of Technology, Associate Professor, 工学部, 助教授 (60016649)
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| Co-Investigator(Kenkyū-buntansha) |
SAKURAI Minoru Tokyo Institute of Technology, Assistant, 工学部, 助手 (50162342)
CHUJO Riichiro Tokyo Institute of Technology, Rrofessor, 工学部, 教授 (60016285)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Piezoelectric Polymer / Vinylidene Cyanide / Alternating Copolymer / NMR Spectroscpy of Polymer / 高分子のNMR / エンタルピー緩和 |
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| Research Abstract |
Piezoelectricity in polymers is in general a result of combination of several factors. Recently,high piezoelectric activity has been found in some vinylidene cyanide(VDCN) copolymers. They are new type piezoelectric polymers, since they are essentially amorphous. The molecular origin of their high piezoelectric activity has not yet become fully understood because of the lack of structural information concerning the amorphous state.
In the present work, microstructure and molecular dynamics have been in- vestigated by measuring high-resolution 1H and ^<13>C NMR spectra and DSC enthalpy relaxation for VDCN copolymers with vinyl acetate,vinyl benzoate,methyl methacrylate, and styrene in order to elucidata the molecular origin of piezoelectric activity. The piezoelectric activity of former two copolymers is high,while that of the latter two is very low.
It was found that the compositional sequence distribution and tacticity of these copolymers were not largely different from each other,namely,all copolymers have highly alternating sequences with non-stereoregular structures. Thus the reason,why some VDCN copolymers show but another VDCN copolymers do not show high piezoelectricity,should be found in the factors other than the microstructures. From the analysis of conformation in solution using 1H NMR spectra, it was found that the solvent used for the film casting is one of important factors to obtain high piezoelectricity. 1H spin lattice relaxation times in the rotating frame and enthalpy relaxation times were also measured ,and it was suggested that the chain flexibility is also the important factor to attain to high piezoelectricity.
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