Polyisophthalamides with benzoyl pendent groups: Synthesis, characterization, and evaluation of properties

Polyisophthalamides containing benzoyl pendent groups were prepared from 5‐benzoylisophthaloyl chloride and seven aromatic diamines, and their properties were compared with those of unsubstituted polyisophthalamides. The incorporation of one pendent benzoyl group per repeat unit brought about a decrease in the glass transition temperature of 10–30°C, relative to the unmodified polymers, while the thermal resistance (programmed TGA) remained unchanged or went down slightly. Other properties investigated were mechanical properties, solubility, and water absorption.