To enhance the catalytic copolymerization of CO2 and propylene oxide catalyzed by zinc glutarate, the influence of trace of water, ethanol, and propanal on the catalytic activity, the resulted copolymer structure, and the molecular weight and molecular weight. distribution of the copolymer were investigated extensively. The experimental results showed that the catalytic activity decreased remarkably in the presence of either trace of ethanol or water, but increased in the presence of trace of propanal. Both H-1-NMR and C-13-NMR spectra suggested that the content of carbonate linkages of resulted copolymer was not effected obviously in the presence of above-mentioned impurities, giving completely alternating poly(propylene carbonate) (PPC). GPC results indicated that these impurities reduced the molecular weights but broadened the molecular weight distributions of resulted copolymers. Finally, the by-product contents including both propylene carbonate determined by GC and polyether increased with the increase of three impurity concentrations. (c) 2006 Wiley Periodicals, Inc.