Valorization of halogenated polymers

Halogenated polymers constitute a significant fraction of global plastic production and disposal, owing to exceptional performance imparted by halogen atoms that include chemical resistance, hydrophobicity, and flame retardancy. Conventional disposal via landfilling, incineration, or pyrolysis can generate toxic halogenated compounds and forgo opportunities for resource recovery. In this perspective, we survey key recent advances in valorization strategies that exploit the unique reactivities of C–X bonds among fluoro-, chloro-, and bromopolymers. Particular emphasis is given to photocatalysis, electrocatalysis, and mechanochemistry, which allow halogen abstraction and bond scission to occur under relatively mild conditions. This enables halogen recovery from fluoro- and bromopolymers, as well as the conversion of chloropolymers such as PVC into hydrocarbons and oxygenated chemicals, thus enabling simultaneous carbon and halogen circularity. Finally, we outline key challenges and future directions for translating these advances into practical technologies for transforming halogenated polymer waste into valuable resources.