Synthesis and Study of Oxygen Bridged Liquid Crystalline Copolyesters

Abstract

Six new thermotropic liquid crystalline random copolyesters with ethereal linkages were prepared from mesogenic 4,4'-oxybis(benzoic acid) by direct polycondensation with different aromatic diols in pyridine solution. Diphenylchlorophosphate (DPCP) was employed as the condensation agent. The solution viscosity numbers ranged from 0.41-0.81 dL/g. The glass transition temperature of these polymers were determined by thermal studies (DSC and optical polarizing microscopy) and found to lie between 41.4 and 61.5 ºC. Spectral studies (¹H, ¹³C NMR and FT IR) gave an insight about the microstructure and copolymer compositions. The polyester composite film was exposed to UV irradiation to find changes in morphology by SEM analysis.