Macromolecules, Vol.48, No.18, 6457-6464, 2015
Expanding the ATRP Toolbox: Methacrylate Polymerization with an Elemental Silver Reducing Agent
The atom transfer radical polymerization (ATRP) of methacrylates using Ag-0 as a reducing agent was carried out. Optimized reaction conditions enabled the controlled preparation of polymethacrylates using elemental silver and a CuBr2/PMDETA catalyst, with polymer dispersity values down to D = 1.06. In these reactions, the formation of AgBr was observed as a dark coating on the surface of the silver wire; however, the AgBr coating had minimal effect on polymerization, and the same silver wire could be used in several consecutive reactions without elaborate cleaning. Different polymethacrylates were prepared with good control, and a poly(methyl methacrylate)-b-poly(benzyl methacrylate)-b-poly(ethyl methacrylate)-Br triblock copolymer was prepared with a molecular weight of 32 200 and a dispersity off) = 1.07. Additionally, it was shown that silver can act as a supplemental activator in the generation of radicals from ethyl a-bromophenylacetate, with a rate constant of surface activation of k(a0)(app) = 9.1 X 10(-6) cm s(-1).