Emerging green approaches for valorization of plastics with saturated carbon backbones

Plastics possess highly unsustainable linear life cycles that are environmentally damaging. With low recycling rates worldwide, plastics upcycling is emerging as a promising alternative by using these abundant waste products as chemical feedstock for the production of materials and essential chemicals of higher economic value. However, the saturated C–C polymer backbones of polymers constituting ~60% of all plastic waste are unreactive and challenging to upcycle, often necessitating energy-intensive processes. This review examines state-of-the-art sustainable approaches employing the Principles of Green Chemistry to functionalize or cleave these unreactive polymer backbones, including alternative solvents, Earth-abundant metal catalysis, emerging low-energy approaches, and biocatalysis. Such sustainable strategies will enhance the attractiveness and practical feasibility of plastics upcycling to achieve a circular materials economy.