One-pot terpolymerization of CHO, CO 2 and L-lactide using chloride indium catalysts.

Ring-opening copolymerization reactions of epoxides, carbon dioxide and cyclic esters to produce copolymers is a promising strategy to prepare CO-based polymeric materials. In this contribution, bimetallic chloride indium complexes have been developed as catalysts for the copolymerization processes of cyclohexene oxide, carbon dioxide and L-lactide under mild reaction conditions. The catalysts displayed good catalytic activity and excellent selectivity towards the preparation of poly(cyclohexene carbonate) (PCHC) at one bar CO pressure in the absence of a co-catalyst. Additionally, polyester-polycarbonate copolymers poly(lactide--cyclohexene carbonate) (PLA--PCHC) were obtained an one-pot one-step route without the use of a co-catalyst. The degree of incorporation of carbon dioxide can be easily modulated by changing the CO pressure and the monomer feed, resulting in copolymers with different thermal properties.