Two different initiator/transfer agents (inifers) containing an alkoxyamine and a dithiobenzoate were synthetized and used to trigger out either reversible addition-fragmentation chain transfer (RAFT) polymerization or nitroxide-mediated polymerization (NMP). a-Dithiobenzoate-?-alkoxyamine-difunctional polymers were produced in both cases which were subsequently used as precursors in the formation of block copolymers. This synthetic approach was applied to N-isopropylacrylamide (NIPAM) or polyethylene oxide methacrylate (EOMA) to form a,?-heterodifunctional homopolymers via RAFT at 60 degrees C which were chain extended with styrene by activating the alkoxyamine moiety at 120 degrees C. Under such temperature conditions, it is proposed that a tandem NMP/RAFT polymerization is initiated producing a simultaneous growth of polystyrene blocks at both chain-ends. Self-assembled nanostructures of these amphiphilic block copolymers were evidenced by scanning electron microscopy. (C) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012