We reported the synthesis and morphology of a novel alkyne-functionalized diblock copolymer (di-BCP) poly(methyl methacrylate-random-propargyl methacrylate)-block-poly(4-bromostyrene). The di-BCPs were synthesized by atom transfer radical polymerization and postpolymerization deprotection, with good control over molecular weight and polydispersity index. Microphase separation in bulk di-BCPs was confirmed by thermal analysis, small-angle X-ray scattering, and transmission electron microscopy. Microphase-separated morphologies were also observed in thin films, and the orientation of the microdomains can be conveniently controlled by annealing under different solvents. (C) 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012