One-component air-stable iron catalysts for the ROCOP of epoxides and cyclic anhydrides

Abstract

Bio-sourced polyesters have been synthesized by ring-opening copolymerization reaction of epoxides and cyclic anhydrides using air-stable one-component heteroscorpionate Fe(III)-halide catalysts. Alternating polyesters from renewable resources such as limonene oxide, endo/exo-carvone oxides and succinic and citraconic anhydrides, have been obtained with reasonable molecular weight, narrow dispersity, and high percentage of ester linkages under air conditions. There are few examples of air-stable “one-component” metal-based catalysts in the literature, tending to rely on external additives, and the results hereby reported provide hope that air-stable friendly metals complexes can be effective systems in future sustainable polymerization research. The microstructure and thermal properties of the polyesters synthesized have been investigated and discussed, and for the amorphous copolymers, the Tg values have shown values from 17.5 °C to 128.5 °C.