Biocompatible polymers via aqueous electrochemically mediated atom transfer radical polymerization

The preparation of well-defined polymers via aqueous atom transfer radical polymerization (ATRP) is challenging due to the high activity and limited stability of ATRP catalysts in water. Optimized conditions previously reported for the ATRP of some watersoluble monomers cannot be regarded as universal conditions. Indeed, well-controlled Electrochemically mediated ATRP (eATRP) of oligo(ethylene oxide)methyl ether acrylate (OEOA) and 2-hydroxyethyl methacrylate (HEMA) were achieved by adjusting the conditions in relation to the solubility and reactivity of these monomers and corresponding polymers. Importantly, PEOA with low dispersity and predetermined molecular weight was obtained even with low catalyst loading and high monomer content (up to 50 vol%).Moreover, >90% conversion of HEMA was obtainedwithin 6–7 h, giving PHEMA with dispersity 1.2–1.3. This work confirms eATRP as a versatile, clean technique applicable to a range of water-soluble, biocompatible monomers.