Macroporous poly(vinylpyrrolidone-co-ethylene dimethacrylate) beads by suspension polymerization

Radical suspension copolymerization of 1-vinyl-2-pyrrolidone and ethylene d imethacrylate initiated with 2,2'-azo-bisisobutyronitrile in an aqueous sod ium chloride solution was used to prepare macroporous beads. Cyclohexanol a nd dodecan-1-ol were used as inert diluents in the organic phase to ensure phase separation and the permanent porosity of the resulting product. Magne sium hydroxide as a suspension stabilizer was formed in situ from magnesium chloride and sodium hydroxide. All samples were characterized in terms of particle size and distribution, nitrogen content, specific surface area and water and cyclohexane regain. Particle size was dependent on the concentra tion of magnesium hydroxide in the reaction mixture. (C) 2000 Elsevier Scie nce B.V. All rights reserved.