Semi-rigid thermotropic liquid-crystalline copolycarbonates comprising main-chain hexafluoropentane segments
✍ Scribed by Moriyuki Sato; Yuji Tada; Yusuke Goto; Ken-ichi Mukaida
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 480 KB
- Volume
- 16
- Category
- Article
- ISSN
- 1022-1336
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✦ Synopsis
Abstract
Novel semi‐rigid fluorocarbon‐containing coplycarbonates composed of biphenyl moiety and rigid rod‐like hexafluoropentane chain were prepared by melt polycondensation of 6,6′‐(biphenyl‐4,4′‐diyldioxy)dihexanol (1) and 2,2,3,3,4,4‐hexafluoro‐1,5‐pentanediol (2) with alkylene diphenyl dicarbonates 3 of various aliphatic lengths (m = 6, 8, 10 and 12). The structures of the copolymers 4 were confirmed by FT‐IR, ^1^H and ^13^C NMR spectra and elemental analyses. The thermal and liquid‐crystalline (LC) properties were examined by differential scanning calorimetry (DSC), polarizing microscopy and temperature‐changeable X‐ray analyses. These measurements indicated that the copolymers show well‐defined thermotropic nematic textures and have block‐like sequences. It is suggested that the introduction of the hexafluoropentane chain into the main chain gives more stable LC phases.