Research by Daniel S. Camarda*, Matthew J. Lampe*, Alan J. Lesser*, Philippe Desbois, Klaus Stoll, Claus Gabriel, Rupert Konradi was recently published in the Journal of Applied Polymer Science. Researchers have fabricated graft copolymers from semi-crystalline thermoplastics for polymer upcycling. The copolymer is synthesized by free radical polymerization of a vinyl monomer within the semi-crystalline polymer, below melting, in supercritical CO2 such that amorphous regions are exclusively grafted. Polystyrene-polyamide 6 copolymers showed the highest graft yield as well as improved properties such as high glass transition temperatures, remeltability, controllable hydrophobicity, and tunable grafting molecular weight.