Tuning of activity, induction period and polymer properties of double metal cyanide catalyzed ring-opening polymerizations of propylene oxide by using quaternary ammonium salts

Polymerizations of propylene oxide (PO) have been carried out by using double metal cyanide (DMC) catalyst prepared by reacting ZnCl2 and K3[Co(CN)6] in the presence of tert-butyl alcohol (tBuOH) as a complexing agent. The catalytic activity and the induction period for PO polymerizations catalyzed by DMC are tunable by using various quaternary ammonium salts (QAS) as external additives. The DMC/QAS binary catalyst improves polymer properties as well such as molecular weight, molecular weight distribution, viscosity, and unsaturation level.