Thermotropic copolyesters of a series of aromatic diols with phenylterephthalic acid and 4,4′‐oxybisbenzoic acid

Abstract

AbstractWholly aromatic, liquid crystalline, main chain copolyesters derived from various linearly substituted aromatic diols with mixtures of 2‐phenylterephthalic acid and a nonlinear aromatic dicarboxylic acid, 4,4′‐oxybisbenzoic acid, were prepared by acidolysis condensation polymerization reactions and characterized for their liquid crystalline properties. The formation of a liquid crystalline phase at elevated temperatures was not prevented by the introduction of up to 50 mol % of the nonlinear diacid in the copolymers, and all of those copolyesters exhibited nematic liquid crystalline phases. Furthermore, the inclusion of a nonlinear monomer was not as effective as was the presence of a phenyl substituent in decreasing the melting transition of these copolymers. All of the copolymers had high glass transition temperatures and high thermal stabilities. © 1993 John Wiley & Sons, Inc.