Synthesis and characterization of new polyesters having unsaturated groups from bis[4-(alkyloxy)benzilidene]succinic anhydride

Abstract

Several monomeric benzilidene anhydrides (2asimilar tod) having n-alkyloxy groups with various n-alkyl chain lengths were prepared by Stobbe condensation of diethyl succinate with 4-(n-alkyloxy)benzaldehyde (1a,b) followed by hydrolysis of the succinates and cyclodehydration of the benzilidenated succinic acids. Configurational isomerism of the monomer was investigated by spectroscopic means. It was found that monomers (2asimilar tod) exist in (ZZ)-isomeric structure. Polymerization was carried out in bulk at 150-210 degreesC range in nitrogen flow. The chemical structure and thermal properties of the polymers were characterized by spectroscopic means, TGA and DSC. Their properties highly depended on their chemical structures in accordance with a side chain length.