One-Step Conversion of BisphenolAPolycarbonate into Aliphatic Polycarbonate Polyols for Recyclable Polyurethane Production

The growing accumulation of plastic waste emphasizes the pressing need for sustainable recycling technologies. In this study, we present a one-step conversion of bisphenol A- based polycarbonate (BPA-PC) waste into aliphatic polycarbonate (APC) polyols using diols with varying chain lengths. The resulting APC polyols were subsequently utilized as soft segments in combination with 4,4′-methylene diphenyl diisocyanate (MDI) in the production of thermoplastic polyurethanes (TPUs). These TPUs exhibited excellent mechanical properties, with a maximum tensile strength of 58 MPa and elongation at break of 397%, as well as robust hydrolytic stability, maintaining performance even after prolonged water exposure. Notably, the APC-based TPUs exhibited excellent recyclability through organocatalytic depolymerization, which facilitated the simultaneous hydrolysis of both urethane and carbonate bonds. This process yielded the selective formation of 4,4′-methylenedianiline (MDA), an industrial precursor to MDI, and 1,4-butanediol (1,4-BD) with remarkably high yields of 96% and 95%, respectively. This work provides valuable insights into designing closed-loop recyclable polymers by upcycling plastic waste via a straightforward process. Additionally, it offers a practical and impactful solution for the end-of-life management of upcycled polyurethane products, thereby contributing to a circular plastic economy.