Synergy between Electrochemical ATRP and RAFT for Polymerization at Low Copper Loading.

A dual-concurrent atom transfer radical polymerization/reversible addition-fragmentation chain-transfer (ATRP/RAFT) system is used to control a radical polymerization by electrochemical reduction of small amount of copper complexes in the presence of a chain transfer agent (CTA). Electrochemical ATRP conditions provide a continuous supply of radicals, while the CTA aids the control over molecular weight and dispersity of poly(n-butyl acrylate), even in the presence of low ppm amounts of catalyst. The polymerization could be turned "on" and "off" by shifting electrolysis potential. With as low as 10 ppm of Cu catalyst, addition of only 2% CTA (with respect to the ATRP initiator) improves control by decreasing dispersity from Ð = 1.41 to Ð = 1.25.