Used as a key intermediate in the synthesis of high-performance polymers, particularly polyetherimides and polyesters. Its bifunctional acid chloride groups enable it to act as a crosslinking agent, enhancing thermal stability and mechanical strength in polymer chains. Commonly applied in aerospace, electronics, and automotive industries for manufacturing heat-resistant coatings, insulating materials, and structural composites. Also utilized in the preparation of specialty membranes for gas separation due to its rigid aromatic structure and reactivity.