BPDA is an aromatic tetracarboxylic dianhydride compound, and one of the most important dianhydride monomers for synthesizing high-performance polyimides (PI). Due to its rigid biphenyl structure and symmetric molecular backbone, BPDA significantly enhances the thermal stability, mechanical strength, and chemical resistance of polyimide materials. Consequently, it is widely used in aerospace, electronics, electrical insulation, and flexible display technologies