Incorporation of ether linkage in CO 2/propylene oxide copolymerization by dual catalysis

Abstract

Carbon dioxide (CO 2)/propylene oxide copolymerization using dual catalyst composed of Salen-cobalt(III) complex bearing four quaternary ammonium salts (a highly active poly(propylene carbonate) catalyst) and a double metal cyanide (DMC, a highly active poly(propylene oxide) catalyst) afforded poly(propylene carbonate-co-propylene oxide) through shuttling of the growing polymer chains between the two catalyst sites. Results of 1H NMR, 13C NMR, DSC studies supported formation of genuine poly(propylene carbonate-co-propylene oxide), not a mixture of poly(propylene carbonate) and poly(propylene oxide). The carbonate fraction was variable by tuning the ratio of the two catalysts and the CO 2 pressure. © 2011 Elsevier Ltd. All rights reserved.