Recent developments in catalytic activation of renewable resources for polymer synthesis

This review describes the application of organometallic and inorganic complexes as initiators and catalysts for polymerizations using renewable resources. It focuses on the ring-opening polymerization of lactide and the alternating copolymerization of carbon dioxide and epoxides. For lactide ring-opening polymerization, a general background to the reaction mechanism, kinetics, stereochemical control and polymerization control is presented. This is followed by reviews of the use of groups 3 and 13 complexes as initiators. Group 3 complexes show excellent rates, amongst the fastest reported for this polymerization, and in some cases stereocontrol. The group 13 complexes have good precedent for stereocontrol; recent advances using heavier group 13 elements, In and Ga, are highlighted. For the alternating copolymerization, an overview of the reaction kinetics, mechanism and control is presented. Recent advances in the use of catalyst operating at low pressure and dinuclear catalysts are presented.