The synthesis of five homopolymers (PS)(3) and the corresponding diblock copolymer 3-arm stars of the (PS-b-P2VP)(3) type is reported through atom transfer radical polymerization. Such star homo- and copolymers are prepared without any addition of solvent (bulk polymerization). The kinetics study results lead to the ability of predicting the best polymerization time with high values of monomer to polymer conversion, sufficient polydispersity indices and average molecular weights. Molecular characterization through size exclusion chromatography, viscometry, low-angle laser light scattering, proton and carbon nuclear magnetic resonance spectroscopy (H-1 NMR and C-13 NMR, respectively) verified the successful synthesis of both homopolymer and copolymer 3-arm star-like architectures. Furthermore, the morphological characterization of the final copolymers is reported through transmission electron microscopy studies verifying the self-assembly without any indication of homopolymer or Cu(I) traces. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 23-32