Copolymerization of cyclohexene oxide with carbon dioxide catalyzed by Zn-Co double metal cyanide complex

Double metal cyanide complexes based on Zn-3[Co(CN)(6)](2) were prepared and used for copolymerization of cyclohexene oxide with carbon dioxide. The catalytic characteristics and the effect of preparation conditions on catalytic performance and product composition were investigated. The results showed that these catalysts could catalyze copolymerization effectively. The catalytic efficiency could reach over 6 000 g/g when the catalyst content was 1..8 X 10(-4), and the products were confirmed to be nearly alternative copolymers by FT-IR and H-1 NMR. The effects of complexing agents and zinc halides (ZnX2, X = F, Cl, Br, I) on catalytic performance were studied. The catalytic efficiency was influenced by the kind of complexing agents and zinc halides employed in preparation of catalysts. However, the composition of copolymers was only influenced by the kind of zinc halides. Among those complexing agents and zinc halides investigated, tert-butanol and zinc chloride were preferable, respectively. The kinetic study indicated that the initial reaction rate of copolymerization exhibited first order dependence on the catalyst content, and average activation energy of copolymerization was 41.6 kJ/mol.