AUTHOR=Kan Ze , Luo Wenlong , Shi Tong , Wei Chuanzhi , Han Binghao , Zheng Dejuan , Liu Shaofeng 

TITLE=Facile Preparation of Stereoblock PLA From Ring-Opening Polymerization of rac-Lactide by a Synergetic Binary Catalytic System Containing Ureas and Alkoxides

JOURNAL=Frontiers in Chemistry

VOLUME=6

YEAR=2018

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2018.00547

DOI=10.3389/fchem.2018.00547

ISSN=2296-2646

ABSTRACT=<p>Ring-opening polymerization (ROP) of cyclic esters/lactones by efficient catalysts is a powerful method for synthesis of biodegradable and biocompatible polyesters with well-defined structures. To develop catalytic systems that are fast, selective and controlled is a persistent effort of chemists. In this contribution, we report a binary urea/alkoxide catalytic system that could catalyze ROP of <italic>rac</italic>-LA in a fast (over 90% conversion within 1–2 min), stereoselective (<italic>P</italic><sub>i</sub> up to 0.93) and controlled manner, indicated by narrow MW distributions, linear relationship between the monomer conversions and <italic>M</italic><sub>n</sub>s, end-group fidelity, and chain extension experiments. Remarkably, the catalytic system described here is simple, easily prepared, and structurally tunable and thus has versatile catalytic performances.</p>