Nematic and Cholesteric Thermotropic Azoxy Polyesters with Moderately Low Transition Temperatures

Abstract

The synthesis and properties of a new nematic and twisted nematic polyester system based on 4, 4′ azoxy-2, 2′methylphenyl moiety separated by flexible spacers with an asymmetric center in the backbone is described. The polymers of the system have moderately low transition temperatures and are well soluble in various solvents. The polyesters described flow easily and give characteristic textures of nematic and cholesteric fluids including selective reflections of light. The thermal properties of these polyesters indicate an increase of isotropisation entropy with the increase of average spacer length.