Future Trends in Polymer Upcycling: Pioneering Depolymerization Strategies for Sustainable Chemical Innovations

The field of polymer upcycling through depolymerization is rapidly advancing, offering innovative strategies to convert waste plastics into valuable small molecules, specialty chemicals, and new polymers. This Perspective highlights key depolymerization methods, including light-driven and catalytic approaches, which enable the breakdown of C–C and C-X bonded polymer backbones under milder conditions than those of traditional pyrolysis. Techniques such as hydrogenolysis, cracking, and selective oxidation efficiently transform polyolefins and polyesters into higher-value products. Specific upcycling pathways yield fatty acids from polyethylene and polypropylene, aminolysis-derived monomers from poly(ethylene terephthalate) (PET), and N-substituted succinimides from poly(succinates), showcasing substantial conversion efficiencies. The integration of engineered depolymerizable polymers enables end-to-end monomer regeneration under controlled conditions, while photocatalytic methods broaden the applicability to thermosets and polyurethanes. Additionally, biotic and abiotic routes for PET highlight the potential for carbon-neutral upcycling, supporting circular economy initiatives. Overall, this emerging landscape of depolymerization-based upcycling is shifting focus from mere monomer recovery to the selective generation of tailored chemical derivatives, offering a comprehensive toolkit for addressing plastic waste challenges and advancing sustainable chemistry.