Amphiphilic Polymer Conetworks Prepared by Controlled Radical Polymerization Using a Nitroxide Cross-linker

Tandem atom transfer radical polymerization (ATRP) and nitroxide-mediated radical polymerization (NMRP) were used to synthesize a polystyrene-co-poly(acrylic acid) (poly(St-co-AA)) network, in which the two components were interconnected by covalent bond. First, a specific cross-linker, 1,4-bis(1'-(4 ''-acryloyloxy-2 '',2 '',6 '',6 ''-tetramethylpiperidinyloxy)ethyl)benzene (di-AET), a bifunctional alkoxyamine possessing two acrylate groups, was copolymerized with tert-butyl acrylate through ATRP to prepare a precursor gel. The gel was then used to initiate the NMRP of styrene to prepare poly(St-co-(t-BA)) conetwork, in which the cross-linkages are composed of polystyrene segments. Finally, the poly(St-co-(t-BA)) conetwork was hydrolyzed to produce amphiphilic poly(St-co-AA) conetwork. The resulting gels show swelling ability in both organic solvent and water, which is characteristic of amphiphilic conetworks. (c) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4141-4149, 2010