Stereoselective Ring-opening Polymerization of rac-Lactide by Bulky Chiral and Achiral N-heterocyclic Carbenes  

作　　者：Hui Li Bai-Ru Ai Miao Hong 

机构地区：[1]Key Laboratory of Marine Materials and Related Technologies,Key Laboratory of Marine Materials and Protective Technologies of Zhejiang Province Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]State Key Laboratory of Organometallic Chemistry,Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,Shanghai 200032,China

出　　处：《Chinese Journal of Polymer Science》2018年第2期231-236,共6页高分子科学（英文版）

基　　金：financially supported by the Science and Technology Commission of Shanghai Municipality(No.17JC1401200)

摘　　要：Despite the extraordinary success has been achieved in metal catalyst-promoted stereoselective ring-opening polymerization（ROP） of rac-lactide（rac-LA）, well-controlled stereoselective rac-LA ROP by organic catalyst still remains a scientific challenge. Here we report our investigations into organocatalytic stereoselective ROP of rac-LA by utilizing novel bulky chiral and achiral N-heterocyclic carbenes（NHC）, 1,3-bis-（1′-naphthylethyl）imidazolin-2-ylidene. The effect of polymerization conditions（e.g. solvent, temperature, alcohol initiator） on ROP behavior by these bulky NHCs has been fully studied, leading to the formation of isotactic-rich stereoblock polylactide（Pi = 0.81） under optimized conditions with high activity（Conv. = 98% in 30 min） and narrow molecular weight dispersity（D = 1.05）.Despite the extraordinary success has been achieved in metal catalyst-promoted stereoselective ring-opening polymerization（ROP） of rac-lactide（rac-LA）, well-controlled stereoselective rac-LA ROP by organic catalyst still remains a scientific challenge. Here we report our investigations into organocatalytic stereoselective ROP of rac-LA by utilizing novel bulky chiral and achiral N-heterocyclic carbenes（NHC）, 1,3-bis-（1′-naphthylethyl）imidazolin-2-ylidene. The effect of polymerization conditions（e.g. solvent, temperature, alcohol initiator） on ROP behavior by these bulky NHCs has been fully studied, leading to the formation of isotactic-rich stereoblock polylactide（Pi = 0.81） under optimized conditions with high activity（Conv. = 98% in 30 min） and narrow molecular weight dispersity（D = 1.05）.

关 键 词：POLYLACTIDE Ring-opening polymerization STEREOSELECTIVITY Organic catalyst N-heterocyclic carbene 

分 类 号：O631.5[理学—高分子化学]