Thermotropic Polyarylates from Methylhydroquinone and 4, 4′-Diphenyldicarboxylic Acid

Abstract

High molecular weight polyarylates derived from methylhydroquinone and 4, 4′-diphenyldicarboxylic acid (CH₃-HQ/BB) were prepared by melt polymerzation, followed by solid-state polymerization. Injection molded test pieces of CH₃-HQ/BB showed high flexural modulus (30.8 GPa, 0.8 mm thickness). SEM of the fractured injection molded test pieces showed few needle-like fibrils but showed plate-like structures. DSC thermograms of CH₃-HQ/BB showed two endotherm peaks (304-310 and 362-370°C). The lower endotherm peak was confirmed to be a crystal-crystal transition by the X-ray diffraction patterns.