Ordering processes in the 2,6‐hydroxynaphthoic acid (HNA) rich copolyesters of p‐hydroxybenzoic acid and HNA

Abstract

Abstract The nature of the microstructure of several copolyesters of p‐hydroxybenzoic acid (HBA) and 2,6‐hydroxynaphthoic acid (HNA) with compositions of 20/80, 24/76, and 30/70 was studied. Annealing the compositions at 50–80 °C below the crystal nematic transition resulted in a physical ordering process, whereas heating the polymers at the crystal nematic transition resulted in a more highly ordered phase. The ordered phases could be randomized by heating to a temperature at or above the transition of the more highly ordered phase.