Butane-1,2,3,4-tetracarboxylic dianhydride (BTCA) is primarily utilized as a non-formaldehyde crosslinking agent in the textile industry for finishing cotton and other cellulosic fabrics, imparting wrinkle resistance, enhanced durability, and flame retardancy through esterification with hydroxyl groups on cellulose. It is also employed in polymer chemistry as an intermediate for synthesizing polyimides, polyamides, and epoxy resins, where it improves thermal stability, mechanical properties, and chemical resistance. Applications include high-performance coatings, adhesives, composites for aerospace and electronics, and insulation materials. The dianhydride functionality enables efficient reactions with diamines, diols, or epoxides to form robust thermosetting networks. Additionally, it serves as a dye-fixing agent in textile processing to boost color fastness.