Visible-light-induced reversible complexation mediated living radical polymerization of methacrylates with organic catalysts

Photoinduced reversible complexation mediated polymerization (photo-RCMP) was developed as a new photoinduced living radical polymerization (LRP). It consisted of an alkyl iodide as a dormant species and an amine as a catalyst, using visible light at 350-600 nm. The amine catalysts include such common compounds as tributylamine. Mechanistically, the polymerization is induced by the photolysis of the dormant species and dormant species/catalyst complex, which frequently occurs as the main activation process. The polymer molecular weight and its distribution (M_w/M_n = 1.1-1.4) were well controlled in the polymerizations of methyl methacrylate and some functional methacrylates up to fairly high conversions in many cases. Perfectly no polymerization took place without photoirradiation, meaning that the system is an ideal photo "on"-"off" switchable system. The polymerization rate was also finely tunable by the external irradiation power. Attractive features of photo-RCMP include the uses of inexpensive compounds and visible light, good polydispersity control, good tolerance to functional groups, and fine response to external photoirradiation.