Tosyl iodide – a new initiator for the photo-controlled iodine transfer polymerization of methacrylates under sunlight irradiation

A very simple photo-controlled iodine transfer polymerization system consisting only of methacrylate monomers, solvent (dimethylacetamide), and initiator (tosyl iodide) under violet and sunlight irradiation is reported. In this report, the tosyl iodide initiator is used for the first time for the successful photo-controlled polymerization of methyl methacrylate (MMA), which yields a well-controlled PMMA under irradiation with violet light (Đ = 1.28) and sunlight (Đ = 1.23). This system does not require additional photocatalysts or iodide salts to control polymerization. In addition, the presented polymerization system provides tight control over activation and deactivation in response to “on–off” switching cycles. The polymerization system under sunlight has been successfully extended to polymerize several methacrylate monomers such as glycidyl methacrylate (GMA), ethyl methacrylate (EMA), n-butyl methacrylate (n-BMA), and 2-hydroxyethyl methacrylate (HEMA) in a very well controlled manner (1.04 ≤ Đ ≤ 1.31).