Sustainable base-mediated chemical upcycling of poly (propylene carbonate) to β-hydroxy sulfides and oxides

Abstract

We present a cesium carbonate–mediated method to upcycle poly(propylene carbonate) (PPC) waste into β-hydroxy sulfides, selenides, and phenoxides via selective thermal depolymerization. The process tolerates diverse nucleophiles, including those from multilayer plastics. Mechanistic studies support a cesium aryl thiolate–driven nucleophilic degradation. The β-hydroxy products are easily functionalized, and the base is recyclable, offering a sustainable route for PPC valorization.