COMPOSITION HETEROGENEITY OF LIQUID-CRYST AL ALKYLENEAROMATIC P-HYDROXYBENZOIC ACID-BASED COPOLYESTER

Condensation of poly(ethylene terephthalate) with p-hydroxybenzoic aci d was investigated. The causes that lead to formation of the fraction rich in poly(ethylene terephthalate) blocks were examined. In order to decrease composition heterogeneity, preliminary acidolysis of the ini tial polyester by acetic acid and dosed feed of p-acetoxybenzoic acid were found to be effective. The reaction examined in this study lies w ithin the framework of the poorly studied method for the synthesis of chain-heterogeneous copolyesters by reacting in melt a monomer or mono mers with the initial polyester. Principal features characteristic of this reaction are discussed.