Co-upcycling of polyvinyl chloride and polyesters

Catalytic upcycling of plastic wastes to valuable chemicals offers the opportunity to simultaneously address the enormous environmental problems associated with plastics and achieve the circular economy. However, the upcycling of plastic wastes containing polyvinyl chloride (PVC) is particularly challenging due to the interference of chlorine, which can be released during PVC depolymerization and deactivate the catalyst. Here we present a catalytic process for the co-upcycling of PVC and polyethylene terephthalate (PET). By using a chlorine-containing ionic liquid as the catalyst/solvent and ZnCl2 as Lewis acid catalyst, with in situ utilization of PVC-released chlorine, we successfully converted PET into terephthalic acid and 1,2-dichloroethane with high yields. The results reveal that chlorine from PVC, previously considered detrimental to the transformation of other polymers and the cause of catalyst poisoning, can actually have a positive role in the upcycling of plastic wastes. This work can incentivize further progress in plastics upcycling and pave the way to sustainable plastic wastes management, moving societies one step forward towards realizing the circular economy.