Enzymatic Ring-Opening Polymerization of Lactones: Traditional Approaches and Alternative Strategies

Biodegradable polymers such as polylactides and other polylactones and their synthesis gain progressively importance. Enzymatic ring-opening polymerization (eROP) is the next step sustainable synthesis of polyesters, also suitable for biomedical applications due to high selectivity and lack of toxic agents. The possibility for applying diverse reaction media ranging from traditional bulk and organic media to greener alternatives such as aqueous media, ionic liquids, and supercritical fluids may allow designing alternative non-conventional processes with less environmental footprint. Target success criteria such as high molecular weight and uniformity of polymers, and conversion of monomers have to be carefully evaluated in these diverse media. Herein we discuss the influence of different reaction media and conditions such as water content, temperature and time on the polymer sizes achieved in eROPs and various approaches to improve the molecular weight and uniformity of polymers.