Mesomorphic Polymers-l: Thermotropic Liquid Crystalline Polymers from p-Hydroxybenzoic Acid†;

Abstract

Homopolymerization of p-hydroxybenzoic acid was carried out by using thionyl chloride as condensing agent. The Solvent and Polymerization temperature were varied to evaluate the effect of these parameters on the resultant homopolymer. The number of polymeric samples obtained by this method exhibit thermotropic nematic and smectic mesophases. The mesomorphic properties are normally obtained when the solvent is non-polar and the polymerization temperature is low. Polar solvents and/or higher polymerization temperatures lead to non-mesogenic character. The viscosity measurements of polymeric samples help to explain the non-mesogenic character of certain polymeric samples. The role of intermolecular hydrogen bonding in the polymeric samples is also discussed.