本研究以分散聚合法製備均一粒徑聚苯乙烯(PS)微米球，並對反應條件溶劑、反應溫度、起始劑偶氮二異丁腈(AIBN)用量、穩定劑聚乙烯基吡咯烷酮(PVP)用量進行探討。 以異丙醇為反應溶劑時，因為異丙醇和穩定劑PVP相溶性不佳，核與核之間劇烈碰撞，造成PS微球之粒徑均一度差。而以乙醇或甲醇為反應溶劑時則能成功製備均一粒徑PS微米球。 PS微米球之平均粒徑，隨反應溫度、起始劑AIBN用量增加而大；隨穩定劑PVP用量增加而變小。以乙醇和甲醇為反應溶劑時，所能製備得最大粒徑分別為2.52μm和2.92μm。此外，在乙醇或甲醇溶劑下可以藉由微量(≤5%)添加共溶劑(甲苯或丁酮)來增加PS微米球粒徑。這是因為共溶劑可以增加臨界鏈長(Critical chain length)進而增加PS微球粒徑。 ;The preparation conditions , solvents, reaction temperature, the amount of initiator 2,2′Azobisisobutyronitrile(AIBN) and stabilizer Polyvinylpyrrolidone(PVP),of monodisperse polystyrene (PS) microspheres by dispersion polymerization were investigated. When isopropyl alcohol (IPA) was used as reaction solvent, the compatibility between IPA and PVP was poor. The nuclei collided intensely. So the particle size of PS microspheres was not uniform. On the other hands, monodisperse PS particle was obtained by using ethanol (EtOH) or methanol (MeOH) as solvents. PS particle size was increased with increasing reaction temperature and amount of AIBN and with decreasing amount of PVP. The maximum size of monodispersemicrospheres prepared by EtOH and MOH were 2.52μm and 2.92μm, respectively. In addition, the PS particle sizes were increased by adding few amount (≤5%) of co-solvent (toluene or methyl ethyl ketone) in EtOH or MeOH solvents, respectively.It was considered that co-solvent was able to increase the critical chain length of PS to increase PS particle size.