Imino‐Pyrrole Zn(II) Complexes for the Rapid and Selective Chemical Recycling of Commodity Polymers

Three imino-pyrrole zinc complexes were prepared and applied to the rapid degradation of polylactic acid (PLA) and the depolymerization of bisphenol A polycarbonate (BPA-PC) and polyethylene terephthalate (PET). PLA alcoholysis proceeded rapidly at a range of conditions, including reflux in air. Remarkable activity was demonstrated for the solvent-free methanolysis of PLA at mild conditions with full conversion reached in 11 min at 80 °C. Various conditions were investigated including a range of PLA sources and, importantly, catalyst recycling was demonstrated. The methanolysis of BPA-PC and the glycolysis of PET were achieved, the latter giving full conversion after 1.5 h for all catalysts. The chemical recycling of mixed plastic feedstocks was investigated, including the selective and sequential degradation of a PLA/BPA-PC mixture with a single catalyst and solvent.