Synthesis and microstructure: of aromatic copolyesters

Abstract

The preparation of the homopolymers of 4-hydroxybenzoic acid (HBA) and of 2-hydroxy-6-naphthoic acid (HNA) have been described in the literature and both shown to polymerize as single crystals. However, reports on the synthesis of copolyester of HBA with HNA, polyethylene terephthalate (PET) or biphenol terephthalate (BPT) are not well documented in the published literature. The authors recent studies in this area are combined to provide a reasonably comprehensive picture of the reactions which occur during polymerization, and subsequent processing. The (HBA/HNA) 50/50 copolymer system was selected for this particular study because of its solubility and relative ease of synthesis.