Compositional Analysis of Liquid Crystalline Aromatic Polyesters

Abstract

Compositional analyses of liquid crystalline aromatic polyesters prepared from p-hydroxybenzoic acid (PHB), terephthalic acid (TA) and biphenol (BP) were examined using NMR, IR, pyrolysis-GC and hydrolysis-HPLC. The best method was hydrolysis-HPLC. Hydrolysis of the polymers was carried out under the condition of strong alkalinity and high temperature; the obtained monomers were determined by HPLC. Small amounts of other comonomers and impurities could be determined at the same time. This method is also applicable to the compositional analysis of other systems of liquid crystalline polyesters.