Hydrogen‐Bonded Thermotropic Liquid Crystalline Polyarylate/Amides: Enhanced Thermal Stability, Mechanical Strength, and Long‐Term Performance

ABSTRACT In this paper, a series of liquid crystalline polyarylate/amides were synthesized via a two‐step method, involving 0.0–70.0 mol% of 4‐hydroxybenzoic acid (HBA), 30.0 mol% of 6‐hydroxy‐2‐naphthoic acid (HNA), and 0.0–70.0 mol% of p‐aminobenzoic acid (PABA). Thermotropic liquid crystalline polyarylate/amides with different proportions were prepared through stepwise polycondensation reactions. Data from infrared spectroscopy and polarizing optical microscopy revealed the presence of intermolecular hydrogen bonds and associated fibrous structures in liquid crystalline polyarylate/amides containing aromatic amide units. As a result, with the increase in aromatic amide units, the glass transition temperature ( T g ), melting temperature ( T m ), mechanical properties, melt viscosity, and creep resistance of the liquid crystalline polyarylate/amides were all improved, while their liquid crystalline characteristics were retained. This study provides a novel strategy for the structural design and performance optimization of new engineering plastics.