Nitroxide-Mediated Living/Controlled Radical Polymerization of N,N-Diethylacrylamide

Abstract

Well-defined poly(N,N-diethylacrylamide)s were synthesized for the first time by nitroxide-mediated polymerization. The polymerizations were first performed in toluene solution, using BlocBuilder, a tertiary alkoxyamine based on the nitroxide SG1 (N-tert-butyl-N-[1-diethylphosphono-(2,2-dimethylpropyl)] nitroxide), as an initiator without initial free nitroxide. High monomer conversions were reached, up to completion and the number-average molar masses increased linearly with conversion. However the polydispersity indices (PDI) remained quite high, despite a constant diminution with increasing conversion until a value of 1.9 at high conversion. This could be corrected by the addition of free SG1 at the onset of the reaction, leading to PDI of 1.2 at 93% conversion in the best case. Various alkoxyamine concentrations were used to target different molar masses. The presence of SG1 functionality at the ω-end of the polymer chains was evidenced by size-exclusion chromatography coupled to electospray ionizatio...