Copolymerizations of carbon dioxide and epoxides in the presence of rare earth coordinate catalyst

Carbon dioxide (CO2) as a direct material was copolymerized with epoxides to synthesize new aliphatic polycarbonates, and the copolymerization was catalyzed by the coordinate catalyst composed of rare earth yttrium phosphonate and triisobutylaluminum [Y(P204)3-Al(i-Bu)3]. The epoxides used in this research included epichlorohydrin (ECH) and some new glycidol ether (GE) monomers prepared by the reaction of ECH and phenol or alcohol, such as α-allyl glycidol ether, β-chloroethyl glycidol ether, benzene glycidol ether, m-tolyl glycidol ether, and benzyl glycidol ether. The copolymers were characterized by infrared (IR), 1H nuclear magnetic resonance (-NMR), and dynamic mechanical analysis. The results show that Y(P204)3-A1(i-Bu)3 had better catalytic activity in the copolymerization of CO2 with epoxide, and the copolymerization rate of aryl GE was distinctly higher than that of aliphatic GE. Dynamic mechanical analysis indicated the glass transition temperature Tg of the copolymers GE-CO2 were lower than that of ECH-CO2.