Incorporation of ether linkage in CO2/propylene oxide copolymerization by dual catalysis

Carbon dioxide (CO2)/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 CO2 pressure.

Graphical abstractCO2/PO copolymerization by dual catalysis composed of a highly active poly(propylene carbonate) catalyst and a highly active poly(propylene oxide) catalyst affords poly(propylene carbonate-co-propylene oxide) through shuttling of the growing chains between the two catalyst sites.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► CO2/PO copolymerization using dual catalyst of Salen–Co(III) and DMC. ► Poly(PC-co-PO) was obtained through shuttling of the growing chains. ► The carbonate fraction is tunable.