ABSTRACT
ZnII -complexes bearing half-salan ligands were exploited in the mild and selective chemical upcycling of various commercial polyesters and polycarbonates. Remarkably, we report the first example of discrete metal-mediated poly(bisphenol A carbonate) (BPA-PC) methanolysis being appreciably active at room temperature. Indeed, Zn(2)2 and Zn(2)Et achieved complete BPA-PC consumption within 12-18 mins in 2-Me-THF, noting high bisphenol A (BPA) yields (SBPA =85-91 %) within 2-4â h. Further kinetic analysis found such catalysts to possess kapp values of 0.28±0.040 and 0.47±0.049â min-1 respectively at 4â wt%, the highest reported to date. A completely circular upcycling approach to plastic waste was demonstrated through the production of several renewable poly(ester-amide)s (PEAs), based on a terephthalamide monomer derived from bottle-grade poly(ethylene terephthalate) (PET), which exhibited excellent thermal properties.