Polymer Tacticity Control for Stereoselective Ring-Opening Polymerization of Racemic <i>n</i>-Propylglycolide
Guojie Li, Guangqiang Xu, Xuanhua Guo, Rulin Yang, Hongguang Sun, Qinggang Wang
Abstract
High Resolution Image Download MS PowerPoint Slide The synthesis of stereoregular aliphatic polyesters with superior (bio)degradability and recyclability has been one of the promising areas in material science, which can be achieved through the stereoselective polymerization of cyclic esters. However, it remains a long-standing challenge to achieve tacticity (isotactic and heterotactic) control of aliphatic polyesters in one catalytic system through modulation of the polymerization mechanism. Here we reported a tunable and controllable method for stereoselective polymerization of racemic n -propylglycolide ( n Prgl) based on the analysis of the enantiomorphic site control (ESC) and chain-end control (CEC) mechanisms in the polymerization. The enantiomorphic site control and chain-end control-dominated stereoregular polymerization processes were achieved via adjustable polymerization conditions, producing isotactic poly( n Prgl) with a P m of up to 0.88 (based on ESC) and heterotactic poly( n Prgl) with a P r of up to 0.94 (based on CEC). This understanding of ESC and CEC mechanisms might provide a compelling guidance to the design of stereoselective polymerization.