Abstract
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 (Ɖ = 1.05).
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This work was financially supported by the Science and Technology Commission of Shanghai Municipality (No. 17JC1401200).
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Invited paper for special issue of “Metal-Catalyzed Polymerization”
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Li, H., Ai, BR. & Hong, M. Stereoselective ring-opening polymerization of rac-lactide by bulky chiral and achiral N-heterocyclic carbenes. Chin J Polym Sci 36, 231–236 (2018). https://doi.org/10.1007/s10118-018-2071-5
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DOI: https://doi.org/10.1007/s10118-018-2071-5