BACKGROUND: According to market needs, production of polystyrene microspheres with appropriate particle size is an important daily work of process technique control. Microspheres fabricated by dispersion polymerization have good mono-dispersion, the particle size can be synthesized from several hundred nanometers to a few microns. OBJECTIVE: To investigate the influence of dispersing medium and monomer dosage of dispersion polymerization on the particle size the distribution width of the polystyrene microspheres. METHODS: In the three-necked bottle with mechanical agitation and condensation tube import and export holes, a certain amount of polyvinylpyrrolidone, ethanol and water were added for pre-dispersion at 70 ℃ for 30 minutes, a monomer styrene dissolving azobisisobutyronitrile was slowly dropped, followed by a polymerization reaction at 70 ℃ for 8 hours, then centrifugation, washing and drying, thus monodisperse polymer microspheres were prepared. By scanning electron microscopy, the morphology of polystyrene microspheres was characterized, the particle size of polystyrene microspheres was measured by laser particle size analyzer. RESULTS AND CONCLUSION: Using ethanol/water as the dispersing medium and certain amount of the monomer, the particle size of polystyrene microspheres prepared by dispersion polymerization was at a range of 1-2 μm, and the distribution width was 0.715-0.965.%背景:根据市场需要,生产适当粒度的聚苯乙烯微球是日常工艺控制的一项重要工作.分散聚合得到的微球具有很好的单一分散性,其粒径在几百个纳米到几个微米之间.目的:观察分散聚合法中分散介质及单体用量对聚苯乙烯微球粒径与分布宽度的影响.方法:在配有机械搅拌和冷凝管进出口的三颈瓶中,加入一定量的聚乙烯基吡咯烷酮、无水乙醇和水,在70 ℃下预分散 30 min,缓慢滴加入溶有偶氮二异丁腈的单体苯乙烯,在70 ℃下聚合反应8 h,经离心、洗涤、干燥后即得聚合物微球.通过扫描电镜对聚苯乙烯微球进行了形貌表征,激光粒度分析仪测量聚苯乙烯微球的粒径.结果与结论:当使用一定配比的混合介质无水乙醇和水,在一定的单体用量下,用分散聚合法能制得粒径在1.0～2.0 μm之间,分布宽度在0.715～0.965之间,粒径分布较为均匀的聚苯乙烯微球.
展开▼
