Used primarily as a monomer in the synthesis of high-performance polymers, especially polyethersulfones (PES) and polysulfones. Its rigid aromatic structure and sulfone group contribute to excellent thermal stability, mechanical strength, and resistance to hydrolysis, making it ideal for engineering plastics in aerospace, automotive, and medical devices. It is also employed in membranes for ultrafiltration and dialysis due to its chemical resistance and ability to form porous, durable films. Additionally, it serves as an intermediate in the production of antioxidants and stabilizers for polymers exposed to harsh environments.