Copolymerization of carbon dioxide and epoxide using dialkylzinc/dihydric phenol system as catalyst

Copolymerization of carbon dioxide with epoxypropane (propylene oxide) in the presence of a diethylzinc/dihydric phenol system was examined. A spectroscopic study of the copolymer revealed that one aromatic group was introduced in the copolymer chain. The osmometric number average molecular weight of the copolymer agrees with the molecular weight deduced from spectroscopic studies. The introduction of the aromatic group into the copolymer chain takes place at the initiation step of the copolymerization, and the catalytic activities of the diethylzinc/phenol systems depend on the presence or the absence of the ZnOXOZn group, where X may be phenylene, naphthylene or other aromatic divalent residues.