44isopropylidenediphenol

4,4'-Isopropylidenediphenol, commonly known as bisphenol A (BPA), is an organic compound with the formula C15H16O2. It comprises two phenol rings connected by a central isopropylidene group, with hydroxyl groups at the para positions. The molecule is a colorless solid at room temperature, with a relatively high melting point and limited water solubility; it dissolves in many organic solvents.

Production and structure: BPA is produced industrially by acid-catalyzed condensation of phenol with acetone, followed by purification. The reaction forms the isopropylidene linkage that joins the two phenolic rings and creates the characteristic 4,4'-substitution pattern.

Applications: BPA is a key monomer in the manufacture of polycarbonate plastics and epoxy resins. Polycarbonate plastics yield transparent, rigid materials used in beverage containers, electronics housings, and medical devices. Epoxy resins derived from BPA are widely used as protective coatings for metal cans, varnishes, and structural adhesives.

Safety and regulation: BPA has been studied for estrogenic activity in some biological assays, leading to ongoing research and regulatory review of potential health effects in humans. Regulatory actions vary by jurisdiction. Several regions restrict BPA use in infant feeding bottles and other food-contact materials, and many manufacturers offer BPA-free alternatives for consumer products.

Environmental impact: BPA can migrate from polymer materials during use and disposal. It has been detected in environmental water and sediment, as well as in some consumer products. Regulatory attention focuses on reducing leaching and managing exposure through product design and procurement practices.