Electrochemically mediated atom transfer radical polymerization of n-butyl acrylate on non-platinum cathodes

Traditionally, electrochemically mediated atom transfer radical polymerization (eATRP) is performed with Pt electrodes, but extensive use of such an expensive, rare, and non-functionalizable metal may pose some limitations to the method, owing mainly to the high cost of the experimental setup and the limited natural resources of platinum. As a further development of eATRP, polymerization of n-butyl acrylate in dimethylformamide was investigated employing different cathodic materials: glassy carbon, gold, iron, nickel–chromium, and stainless steel. With all these electrodes, eATRP was fast (conversion >85% in 2 h) and well-controlled (dispersity <1.2) under a wide range of experimental setups. To show the robustness of eATRP with inexpensive non-noble electrodes (i) the catalyst loading was reduced to less than 75 ppm, (ii) the same cathode was reused several times without reactivation, and (iii) undivided cells with all non-platinum electrodes were used. Lastly, all electrodes were stable and did not significantly release metal ions in solution, merely acting as an electron sink for the reduction of the catalyst.