Used as a reactive intermediate in the synthesis of specialty polymers and resins, particularly in epoxy curing agents where it contributes to improved thermal and chemical resistance. Its cyclic structure enhances the rigidity of the final polymer matrix, making it suitable for high-performance coatings, electrical encapsulants, and composite materials. Also employed in the production of plasticizers that require better durability and lower volatility. The anhydride group allows for easy incorporation into polyimide and polyester systems, beneficial in aerospace and electronics industries.