dispersion polymerization of styrene was carried out in ethanol/water medium in the presense of polyvinylpyrrolidone using azobisisobutyronitrile as initiator. The effects of initial mononer concentration

stabilizer concentration

initiator concentration

medium composition and reaction temperature on the size and size distribution of polymer particles were investigated through condition experiments. An ideal recipe was found out from which monodisperse polymer particles of 4.8 μm in diameter were accessible. Then the seed particles of polystyrene produced by dispersion polymerization were further swollen to about four times in diameter by means of dymanic swelling method.And the effects of water-addingrate and the amount of dispersion agent added in the swollen system on swelling process were studied.Finally

the large-size monodisperse polymer microspheres were obtained by polymerizing the monomen-swollen particles.