The commercially available tris(2-aminoethyl) amine (TREN) was used as ligand to mediate the single-electron transfer-living radical polymerization (SET-LRP) of methyl acrylate in dimethyl sulfoxide initiated with the bifunctional initiator bis(2-bromopropionyl) ethane and catalyzed by both nonactivated and activated Cu(0) wire. A comparative study between TREN and tris(2-dimethylaminoethyl) amine (Me-6-TREN) ligand, that is more commonly used in SET-LRP, demonstrated that TREN provided a slower polymerization but the chain-ends functionality of the resulting bifunctional poly(methyl acrylate) was near quantitative and comparable to that obtained when Me6-TREN was used as a ligand. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 35-46, 2012