Controlled/“Living” Radical Polymerization. Homogeneous Reverse Atom Transfer Radical Polymerization Using AIBN as the Initiator

Atom transfer radical polymerization using AIBN/CuBr2/2dNbipy as the initiating system has been successfully carried out for styrene, methyl acrylate, and methyl methacrylate. Well-defined polymers with low polydispersities have been obtained. High apparent initiation efficiencies were observed for both styrene and methyl acrylate polymerizations at 110 °C. With an increase of the [AIBN]o/[CuBr2/2dNbipy]o ratio, apparent initiation efficiency decreased and polydispersity increased. Low initiation efficiencies were observed for the polymerizations of methyl methacrylate at both 110 and 90 °C, with higher polydispersities at higher temperature. The changes in polydispersity with respect to the changes in [AIBN]o/[CuBr2/2dNbipy]o ratio and the temperature can be explained by the differences in the rate of deactivation by the copper(II) halide species.