Dispersion polymerization of 2-hydroxyethyl methacrylate in supercritical carbon dioxide

Herein we report a successful dispersion polymerization of 2-hydroxyethyl m ethacrylate (HEMA) in a carbon dioxide continuous phase with a block copoly mer consisting of polystyrene and poly(1,1-dihydroperfluorooctyl acrylate) as a stabilizer. Poly(2-hydroxyethyl methacrylate) was effectively emulsifi ed in carbon dioxide with the amphiphilic diblock copolymer surfactant, and the successful stabilization of the polymerization simultaneously gave sph erical particles in the submicrometer range with relatively narrow particle size distributions. The initial concentrations of HEMA and the stabilizer and the pressure had substantial effects on the size of the colloidal parti cles. (C) 2000 John Wiley & Sons, Inc.