Recent developments in the UV-visible light-intervened ring-opening polymerization of cyclic esters

Abstract

The synthesis of biodegradable polyesters using the photoinduced ring-opening polymerization (photoROP) technique is well documented in the literature. Controlling the yield, dispersity, and molecular weight of the resulting polymer in principle is a significant challenge. Several different stimuli have been used to initiate the polymerization. Among them, light emerged as a promising stimulus due to the high activity and control shown by the photocatalysts. Switchable catalysts have been used for a long time in other polymerization reactions, but it is a relatively new area of research for ROP reactions. The recent developments in the area of light-intervened ROP of various cyclic esters are discussed in the present paper. We focus on the challenge of initiating photocatalyst active units in such a manner that it generates a species that is chemically distinct in behavior and structure from the precursor. This difference in behavior and structure allows the synthesis of polymers with spatial and temporal control properties.