Dinuclear Mg Complex-Mediated Ring-Opening Polymerization of Lactones: High Molecular Weight and Enhanced Performance

Abstract

Poly(caprolactone) (PCL) is a promising biomaterial for applications in tissue engineering, drug delivery systems, and elastomers. However, low catalytic efficiency hinders the synthesis of PCL with a high molecular weight (MW), greatly impeding its performance. Herein, we address this issue using a bimetallic synergistic catalysis strategy, wherein a dinuclear Mg complex is developed for catalyzing the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) with a low catalyst loading, yielding PCL with an MW as high as 480.0 kg/mol. PCLs with high MWs and low dispersities exhibit enhanced thermal and mechanical properties that are superior to those of PCLs produced with industrial catalysts. In addition, the bimetallic synergistic catalysis strategy enables the controlled ROP of ε-CL and a high tolerance to various chain transfer agents, thus enabling the production of various PCL-based polyols. Moreover, the dinuclear Mg complex can facilitate the ROP of other lactones, thus accessing diverse aliphatic polyesters.