Liquid-crystalline polyimides, 16. Chiral thermotropic copoly(ester-imide)s based on isosorbide and N-(4-carboxyphenyl)trimellitimide

A series of chiral copoly(ester-imide)s was prepared by polycondensation of N-(4-carboxy-phenyl)trimellitimide with mixtures of isosorbide and phenylhydroquinone. All copolyesters are non-crystalline. They form a cholesteric melt, when containing more than 50 mol-% of phenyl-hydroquinone. Containing 5 or 10 mol-% of isosorbide a “Grand-Jean” texture is detected above 300°C and 350°C, respectively.