Photocatalytic HAT for polymer upcycling and degradation

The global surge in plastic waste necessitates sustainable solutions. We demonstrate a versatile approach utilizing photocatalyzed hydrogen atom transfer (HAT) chemistry with iron trichloride (FeCl₃) for both polymer upcycling and degradation. By precisely tuning reaction conditions, we achieved controlled polymer functionalization through the introduction of reversible addition–fragmentation chain transfer (RAFT) agents under aneorbic condition, exemplified by modifications to polycaprolactone (PCL) and poly(vinyl acetate) (PVAc) for graft copolymer synthesis. For polymer degradation, photo-mediated HAT, with FeCl₃ as a photocatalyst, under aerobic conditions effectively degraded a wide range of polymers, including poly(isobutyl vinyl ether) (PIBVE), poly(2,3-dihydrofuran) (PDHF), poly(vinyl acetate) (PVAc), poly(n-butyl acrylate) (PBA), poly(methyl acrylate) (PMA), poly(vinyl chloride) (PVC), poly(dimethyl acrylamide) (PDMA), poly(ethylene oxide) (PEO), poly(oligo(ethylene glycol) methyl ether acrylate) (PEGMEA), and poly(methyl methacrylate) (PMMA). Using low-intensity purple light, FeCl₃ catalysis achieved up to 97% degradation within 3 hours, with precise control through light modulation.