COPOLYMERIZATION OF CARBON DIOXIDE AND CYCLOHEXENE OXIDE CATALYZED BY MONONUCLEAR ZINC SCHIFF BASE COMPLEX

摘要

The synthesis of aliphatic polycarbonates via copolymerization of CO_2 and epoxides has been extensively investigated as effective way for the utilization of CO_2. The researches of the copolymerization focused on the catalyst because of the chemical inertness of CO_2, and a wide variety of promising catalysts have been developed to promote this copolymerization process. Among them, Schiff base complexes including salen(M)X complexes and BDI-Zn complexes were extensively investigated because of their high catalytic activity and living polymerization characteristic. However, the most Schiff base complexes studied were dinuclear Schiff base complexes rather than mononuclear ones even the mononuclear Schiff base complexes were widely used as catalysts in other reactions. In this study, we developed a novel mononuclear zinc Schiff base complex catalyst to catalyze the copolymerization of CO_2 and cyclohexene oxide. The ligand of the complex was prepared from 2-furaldehyde and anthranilate, followed by the coordination reaction between the ligand and zinc acetate. The influences of reaction time and temperature were studied and the reaction conditions were optimized, and the TON of 269.1 and M_n of 4.7×10~4g·mol~(-1) were obtained. The structure of the copolymer was measured by FT-IR and ~1H NMR and the carbonate segment was more than 96%. This work was supported by Foundation of He'nan Educational Committee (14A150016); This work was also supported by Doctoral Fund of Henan Polytechnic University (B2012-052).