Nitroxide-mediated controlled/living free-radical polymerization of methyl methacrylate initiated by the SG1-based alkoxyamine BlocBuilder was successfully performed in bulk at 80-99 degrees C with the help of a very small amount of acrylonitrile (AN, 2.2-8.8 mol%) as a comonomer. Well-defined PMMA-rich P(MMA-co-AN) copolymers were prepared with the number-average molar mass, M-n, in the 6.1-32 kg mol(-1) range and polydispersity indexes as low as 1.24. Incorporation of AN in the copolymers was demonstrated by H-1 and C-13 NMR spectroscopy, and its effect on the chain thermal properties was evaluated by DSC and TGA analyses. Investigation of chain-end functionalization by an alkoxyamine group was performed by means of P-31 NMR spectroscopy and chain extensions from a P(MMA-co-AN)-SG1 macroinitiator. It demonstrated the very high proportion of SG1-terminated polymer chains, which opened the door to block copolymer synthesis with a high quality of control. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 34-47, 2010