Low-Temperature and Solventless Ring-Opening Polymerization of Eutectic Mixtures of l-Lactide and Lactones for Biodegradable Polyesters

Biodegradability is one of the key features for reducing the negative environmental impact of plastic waste disposal; therefore, designing biocompatible polymeric biomaterials with programmable life cycles is urgently needed. Herein, deep eutectic solvent monomers (DESm) composed of l-lactide and various lactones of different molecular weights were formulated to obtain polyesters at low temperatures with the aid of organocatalysts and under solventless conditions. The introduced DESm expand the range of eutectic mixtures capable of undergoing ring-opening polymerization (ROP) to include mixtures of l-lactide with d-valerolactone and d-hexalactone. Extending the toolbox for DESm preparation will allow for the design of polyesters with tailored molecular weight and crystallinity, which are conducive to programmable degradability. ROP of DESm carried out at low temperatures and under solventless conditions holds promise for a sustainable framework for preparing biodegradable polymers for biomedical applications. © 2023 American Chemical Society.