Facile preparation and synergy study of DMC/ZnGA composite catalyst for the synthesis of oligo (propylene‐carbonate) diols

To overcome the weak carbon dioxide (CO2) conversion ability of Zn-Co double metal cyanide (DMC) catalyst, zinc glutarate (ZnGA) catalyst was introduced into the DMC catalytic system and applied for the synthesis of oligo (propylene-carbonate) diols. The DMC/ZnGA composite catalyst (mass ratio = 10:1) exhibited an excellent synergistic effect which had enhanced CO2 activation ability, high yield and good selectivity. In copolymerization process, ZnGA catalyst not only provided activated CO2 for DMC catalyst, but also transferred the propagating chain with more alternating structures to DMC catalyst. Both of the two effects increased the carbonate content in the final products. Overall, DMC catalyst dedicated to the polymer chain growth, while the increased CO2 conversion mainly attributed to ZnGA catalyst. Oligo (propylene-carbonate) diols with carbonate unit content of 45.1 mol%, Mn of 1228 g/mol, W-PC of 4.3 wt% and high yield of 1689 g/g (cat) was obtained.