Enhancement of the Rate of Atom Transfer Radical Polymerization in Organic Solvents by Addition of Water: An Electrochemical Study.

Addition of water to organic solvents enhances the rate atom transfer radical polymerization (ATRP). To understand origin this enhancement, effects H2O on redox properties [CuIITPMA]2+ and [BrCuIITPMA]+ (TPMA=tris(2-pyridylmethyl)amine), ATRP equilibrium (KATRP) activation (kact) constants methyl 2-bromopropionate by [CuITPMA]+ were investigated in CH3CN, DMF DMSO their mixtures with acrylate (MA). E°s complexes allowed evaluation relative halidophilicities [CuITPMA]+, KIIBr KIBr, respectively. KIIBr/KIBr dropped pure solvent/MA when 11 % (v/v) was added, suggesting that hampers stability deactivator [BrCuIITPMA]+. Conversely, both kact KATRP enhanced presence water. In (50/50, v/v), addition increased a factor 2–3, which could explain accelerating effect solvents.