Abstract: Homopolymerization of2,2-dimethyltrimethylene carbonate and its copolymerization with ε-caprolactone (ε-CL) catalyzed by ionic liquid-supported rare earth catalysts were investigated for the first time. The results indicated that this novel catalyst is effective for the homopolymerization and copolymerization. Of all the rare earth catalysts prepared, LaCl3 showed the highest catalytic activity and can be used to prepare poly(2,2-dimethyltrimethylene carbonate) with a viscosity average molecular weight of 3.61×104 and a yield over 88% under mild conditions of ε-CL/La molar ratio=200 and 60 ℃ in toluene. Moreover, both random and block copolymers can be prepared by changing the feed sequence with this catalyst only when ε-CL was polymerized first. When2,2-dimethyltrimethylene carbonate was polymerized first, only homopolymer can be prepared. The copolymers were characterized by1HNMR.

Key words: rare earth, ionic liquid, 2-dimethyltrimethylene, ε-caprolactone, copolymerization