Used as an intermediate in the synthesis of specialty polyesters and copolyesters, particularly in the production of thermoplastic elastomers and engineering plastics. It plays a role in modifying polymer chain structure to enhance flexibility, clarity, and thermal stability. Also employed in the development of resin formulations for coatings and adhesives where controlled reactivity and solubility are required. Its partial ester structure allows for further chemical modification, making it valuable in custom polymer design for films, fibers, and packaging materials.