The synthesis of a molecular brush was accomplished by combining step-growth polymerization and reversible addition fragmentation chain transfer (RAFT) polymerization in a "grafting from'' methodology. A symmetrical N-alkyl urea peptoid sixmer containing alkyne functional groups was prepared using a divergent strategy, and the structure of the product was confirmed using NMR spectroscopy and mass spectrometry. A step-growth process was used to prepare a linear poly(N-alkyl urea peptoid) by reacting the diamine-functionalized N-alkyl urea peptoid sixmer with a diisocyanate. RAFT chain transfer agents were coupled to the poly(N-alkyl urea peptoid) backbone through a copper-catalyzed azide/alkyne cycloaddition reaction. The afforded macro-RAFT agent was used to sequentially polymerize styrene and tert-butyl acrylate block copolymer arms from the poly(N-alkyl urea peptoid) backbone. The tert-butyl groups were removed using dilute trifluoroacetic acid affording hydrophilic polyacrylic acid segments. The molecular brushes were observed to generate micelles in aqueous solution. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 3030-3037, 2011