6028
Macromolecules 2003, 36, 6028-6035
Reverse Atom Transfer Radical Polymerization in Miniemulsion Mei Li and Krzysztof Matyjaszewski* Center for Macromolecular Engineering, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213 Received January 27, 2003; Revised Manuscript Received May 20, 2003
ABSTRACT: Reverse atom transfer radical polymerization was successfully carried out in a miniemulsion system at 70 °C with a doubled solid content (g20%) and 1/6 amount of nonionic surfactant, Brij 98 (2.3 wt % based on monomer, or 0.58 wt % based on the aqueous phase), compared to the previously reported system. Hexasubstituted TREN/CuBr2 and 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (VA044) were employed as a highly active radical deactivator and a water-soluble initiator, respectively. Controlled polymerizations were demonstrated by attaining linear correlations between molecular weights and monomer conversion, and relatively narrow molecular weight distributions ( 106 g/mol) was produced primarily at the beginning of the reaction (