The scale-up of electrochemically mediated atom transfer radical polymerization without deoxygenation

Abstract

The scale-up of Atom Transfer Radical Polymerization (ATRP) from 15 mL to 15 L (scale-up factor 1000) by galvanostatic simplified electrochemically mediated ATRP (seATRP) is disclosed. An electrochemical O2 scavenging cycle was embedded in the ATRP equilibrium to allow self-degassing of the mixture and avoid impractical deoxygenation procedures. Low volume seATRP of acrylamide in water was optimized by studying various reaction parameters, including the concentrations of scavenger, supporting electrolyte, type of initiator and ligand, and catalyst loading. The target reaction was scaled up from 0.015 L to 15 L. At all volumes and up to 15 L, polymerizations were relatively fast and produced well-defined polyacrylamide with narrow molecular weight (MW) distributions. All reactions were powered by renewable electricity, obtained from a photovoltaic plant. Several water-soluble monomers, including (meth)acrylic acid and methacrylamide, were polymerized at pH ranging from 1.0 to 7.4, without compromising the self-degassing mechanism. These results show a feasible scale-up of seATRP and could foster its adoption by polymer industries promoting a more widespread use of controlled radical polymerizations.