Heterogeneous Transfer Dehydrogenation for Catalytic Upcycling of Polyethylene

Polyethylene is the most widely produced plastic globally and a major component of plastic waste. In this work, a chemical recycling process is proposed, yielding telechelic macromonomers as useful building blocks for the polymer industry. Polyethylene was partially dehydrogenated using a reusable, heterogeneous platinum catalyst at moderate temperatures, employing ethylene as a convenient hydrogen acceptor. Various support materials and reaction conditions were investigated, with Pt/ZnO showing the best performance under a constant flow of ethylene. Dehydrogenated samples were subjected to olefin cross‐metathesis with ethyl acrylate using a homogeneous Ru catalyst and then hydrogenated without additional catalyst. The final products, ester‐terminated polyethylene macromonomers, have potential as building blocks for recyclable polyethylene‐like materials and specialized block copolymers. The partially unsaturated polyethylene constitutes a versatile intermediate in the chemical recycling of polyethylene.