One-pot methods for the end-group postpolymerization modification of reversible addition fragmentation chain transfer (RAFT) derived polymers were investigated. Dithioester-terminated polymers were transformed into omega-functionalized polymers through conjugate addition of a variety of acrylates with an intermediate thiol. These methods provide a versatile means of introducing a variety of functionalities onto the polymer terminus, while simultaneously removing the residual dithiobenzoate group. A series of functionalized polymetbylmethaerylate-b-polystyrene (PMMA-b-PS) polymers were synthesized utilizing the developed methods to probe the effect of charged end groups on diblock copolymer phase separation in thin films. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 346-356, 2009