The controlled/living radical polymerization of N-phenyl maleimide (NPMI) was achieved using 2,2'-azobisisobutyronitrile as the initiator and 2-cyanopropyl-2-yl dithiobenzoate as the reversible addition-fragmentation chain transfer agent at 75 degrees C in dichloroethane/ethylene carbonate (60/40, w/w) mixed solvent. The block copolymers of polystyrene-b-polyNPMI and poly(n-butyl methacrylate)-b-polyNPMI were successfully prepared by chain extension from dithiobenzoate-terminated polystyrene and poly (n-butyl methacrylate) to NPMI, respectively. The obtained NPMI-based (co)polymers were characterized by gel permeation chromatography and H-1-NMR spectroscopy. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114:2469-2473, 2009