Selective Upcycling of Mixed Polyesters into Valuable Polysulfone

Selective upcycling of mixed polyester plastic waste into high-value engineering plastics offers a promising strategy to mitigate plastic pollution while promoting a circular plastics economy. Here, we report a catalytic strategy for the selective upcycling of mixed polyester plastics using a magnesium hydroxide–oxygen vacancies catalyst. Polycarbonate and polyethylene terephthalate were selectively depolymerized to bisphenol A (98.4% yield) and bis (2-hydroxyethyl) terephthalate (93.2% yield), respectively, with 100% separation efficiency. The recovered BPA was subsequently used to synthesize high-performance recycled polysulfone, which exhibited superior thermal stability and mechanical strength compared to its commercial counterpart. Life-cycle assessment and techno-economic analysis indicate that the proposed process substantially lowers both environmental impacts and production costs relative to conventional petroleum-based production. This work provides a scalable and sustainable route for mixed polyester waste, advancing circular solutions for polymer waste management.