1991 Fiscal Year Final Research Report Summary
Studies on Nonlinear Optic Properties of Liquid Crystalline Polymers
| Project/Area Number |
02650655
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
高分子物性・高分子材料（含機械材料）
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| Research Institution | Science University of Tokyo |
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Principal Investigator |
KOIDE Naoyuki Science University of Tokyo, Chemistry, Professor, 理学部, 教授 (30084346)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Liquid Crystal Polymer / Nonlinear Optic / Mesogen / Ferroelectricity / Chirality / Mesophase / Cholesteric |
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| Research Abstract |
Main chain type liquid crystalline polymers were prepared from 6acethoxy-2-naphthoic acid[BON6], p-acethoxy benzoic acid[PHB]or p, p'diacethoxybiphenyl[BP]and chiral compound. (s)-(+)-2-(6-acethoxy-2naphthyl)propionic acid[HNPA], D-(+)camphoric acid[DCA]and tartaric acid[TA]were used as a chiral component. The mesomorphic properties of the copolyesters(HNPA-BON6-PHB)were obtained at the contents of HNPA ranging from 10mole% to 50mole%. A finger-printed texture characteristic of cholesteric phase was observed for the copolyester at the 20mole% contents of HNPA. This copolyester exhibited the second harmonic generation (SHG) without orientational process. In order to clarify this effect, copolyester having racemic HNPA was synthesized. The other two chiral copolyesters system did not show the SHG. However, the copolyesters (DCA-BP-PHB) showed a selective reflection in visible region, and the absorption spectrum was shifted from 540nm to 690nm according to decrease of DCA contents in the copolyester. The copolyesters containing tartaric acid exhibited a ferroelectric properties. The chiral component in the polymer would play an important role in order to produce high functional properties.
Two types of liquid crystalline polymers were synthesized by the radical polymerization. A dialkylaminocyanostilbene was used as a mesogenic group in the case of homopolymer, and copolymers having the same dielectric anisotropy were prepared from the Disperse Red 1 as a nonlinear optical (NLO) component and cyanobenzoate as a mesogenic group in the methacrylate.
In the case of cyanostilbene system, only monomer showed SHG, because of the lack of orientation for the polymer.
The SHG value increases with increasing contents of Disperse Red 1 in the mesophase for the copolymer. The enhancement of the SHG value would be deeply attributed to the liquid crystalline orientation.
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