Well-Defined Amphiphilic Graft Copolymer Consisting of Hydrophilic Poly(acrylic acid) Backbone and Hydrophobic Poly(vinyl acetate) Side Chains

A series of well-defined amphiphilic graft copolymers containing hydrophilic poly(acrylic acid) (PAA) backbone and hydrophobic poly(vinyl acetate) (PVAc) side chains were synthesized via sequential reversible addition-fragmentation chain transfer (RAFT) polymerization followed by selective hydrolysis of poly(tert-butyl acrylate) backbone. A new Br-containing acrylate monomer, tert-butyl 2-((2-bromopropanoyloxy)methyl) acrylate, was first prepared, which can be polymerized via RAFT in a controlled way to obtain a well-defined homopolymer with narrow molecular weight distribution (M-w/M-n = 1.08). This homopolymer was transformed into xan-thate-functionalized macromolecular chain transfer agent by reacting with o-ethyl xanthic acid potassium salt. Grafting-from strategy was employed to synthesize PtBA-g-PVAc well-defined graft copolymers with narrow molecular weight distributions (M-w/M-n, < 1.40) via RAFT of vinyl acetate using macromolecular chain transfer agent. The final PAA-g-PVAc amphiphilic graft copolymers were obtained by selective acidic hydrolysis of PtBA backbone in acidic environment without affecting the side chains. The critical micelle concentrations in aqueous media were determined by fluorescence probe technique. The micelle morphologies were found to be spheres. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6032-6043, 2009