Synthesis and characterization of isomeric biphenyl-containing poly(aryl ether–bisketone)s. Part 1.—Polymers derived from 4,4′-(p-fluorobenzoyl)biphenyl and bisphenols

Abstract

A series of amorphous and semicrystalline poly(aryl ether–bisketone)s have been synthesized from bisphenols and 4,4′-bis(p-fluorobenzoyl)biphenyl via nucleophilic aromatic substitution reactions. Model compound studies were carried out with a variety of substituted phenols. 4,4′-bis(p-fluorobenzoyl)biphenyl and 4,4′-bis(p-chlorobenzoyl)biphenyl. The bishalide monomers were synthesized by the reaction of biphenyl-4,4′-dicarboxylic acid with thionyl chloride followed by Friedel–Crafts acylation with the appropriate aryl halide. Potassium carbonate mediated reaction of these monomers in dimethylacetamide or diphenyl sulphone gave high-molecular-weight polymers in excellent yield. Polymers with semicrystalline morphologies were synthesized from soluble high-molecular-weight amorphous precursors with removable bulky substituents. Unlike the corresponding monoketone analogues, the amorphous poly(aryl ether–bisketone)s exhibited poor solubility in a wide variety of solvents, indicative of improved solvent resistance. The glass-transition and melting temperatures of the polymers are among the highest known for poly(aryl ether–ketone)s. In addition, the polymers exhibit excellent thermal stability and afford tough films by compression moulding.