Affiliation:
1. Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied Chemistry Chinese Academy of Sciences Renmin Street 5625 Changchun 130022 P. R. China
2. University of Science and Technology of China Hefei 230026 P. R. China
Abstract
AbstractPolythioesters are important sustainable polymers with broad applications. The ring‐opening polymerization (ROP) of S‐Carboxyanhydrides (SCAs) can afford polythioesters with functional groups that are typically difficult to prepare by ROP of thiolactones. Typical methods involving organocatalysts, like dimethylaminopyridine (DMAP) and triethylamine (Et3N), have been plagued by uncontrolled polymerization, including epimerization for most SCAs resulting in the loss of isotacticity. Here, we report the use of salen aluminum catalysts for the selective ROP of various SCAs without epimerization, affording functionalized polythioester with high molecular weight up to 37.6 kDa and the highest Pm value up to 0.99. Notably, the ROP of TlaSCA (SCA prepared from thiolactic acid) generates the first example of a isotactic crystalline poly(thiolactic acid), which exhibited a distinct Tm value of 152.6 °C. Effective ligand tailoring governs the binding affinity between the sulfide chain‐end and the metal center, thereby maintaining the activity of organometallic catalysts and reducing the occurrence of epimerization reactions.
Funder
China National Funds for Distinguished Young Scientists
National Natural Science Foundation of China
National Key Research and Development Program of China