Thermotropic polyesters with alkylene spacers in the main chain prepared in diphenyl ether

Abstract.

A series of linear thermotropic polyesters derived from 4,4′-dihydroxy-α,ω-diphenoxy alkanes and 4,4′-dichloroformyl-α,ω-diphenoxy alkanes, was prepared by polycondensation in diphenyl ether. This method yielded polyesters that were characterized by a wider persistence range of the nematic phase with respect to the corresponding polyesters prepared by a conventional technique. The linear polyester series was characterized by calorimetric, optical microscopy, and thermogravimetric measurements. The linear thermotropic polyester series formed a stable nematic liquid crystalline phase in the melt and presented high thermal stabilities in the range of 410 – 449 °C.