Used primarily as an intermediate in the synthesis of polyamides and polyesters, enabling the production of high-performance polymers for use in textiles, automotive parts, and engineering plastics. It participates in ring-opening reactions to form long-chain polymers with enhanced thermal and mechanical stability. Also employed in the preparation of specialty chemicals such as adhesives, coatings, and plasticizers due to its reactive anhydride group. Its ability to cross-link with diols and diamines makes it valuable in creating resins with tailored durability and chemical resistance.