Electrochemically Mediated Aqueous Atom Transfer Radical Polymerization of N,N-Dimethylacrylamide

Electrochemically mediated atom transfer radical polymerization (ATRP) of N,N-dimethylacrylamide (DMAA) catalyzed by copper complexes with polydentate amine ligands was studied systematically in water, investigating several reaction parameters such as applied potential, catalyst concentration, ligand structure, monomer and initiator concentrations. Electropolymerizations were successfully performed under both potentiostatic and galvanostatic conditions; in both eATRP modes, reactions were fast (monomer conversion >90 % in less than 1 h) and well-controlled, providing polymers with narrow molecular weight distributions. Despite the low dispersity, chain extension attempts of the obtained polymer were not successful because of partial loss of C-Br chain-end functionality, due to an intramolecular nucleophilic attack. This is an intrinsic drawback of ATRP of acrylamides and although the electrochemical approach allowed preparation of well-defined polymers in a very short time (down to ca. 15 min), loss of chain-end functionality was unavoidable.