微米级单分散聚苯乙烯微球的制备

Preparation of Micron Monodispersed Polystyrene Microspheres

以苯乙烯(St)为单体、偶氮二异丁腈(AIBN)为引发剂、聚乙烯吡咯烷酮(PVP)为分散稳定剂,在乙醇-水反应介质中,采用分散聚合法制备了微米级单分散聚苯乙烯(PS)微球。分别用电镜扫描和激光粒度仪表征了PS微球表面形貌、粒径及粒度分布,探讨了影响PS微球粒径及粒度分布的诸多因素。结果表明,AIBN用量(以单体质量计,下同)大于5.0%或PVP用量(以单体质量计,下同)小于2%时,PS粒子间有聚并现象;当St浓度为10%、AIBN用量为2.5%、PVP用量为5.5%、醇水质量比为90∶10、聚合温度为70℃时,制备的PS微球粒径为1.612μm、粒度分散系数为0.357,微球单分散性及球形度最佳。

In this paper, micron monodispersed polystyrene（PS） microspheres were synthesized by disper-sion polymerization using styrene as monomer, polyvinylpyrrolidone （FVF） as disersion stabilizer, azooi- sisobutyronitrile（AlBN） as initiator and ethanol-water as reaction medium. The influential factors such as initi- ator dosage , dispersion stabilizer dosage and reaction medium ratio on the particle size and size distribution of PS microspheres were investigated. The morphology of PS microspheres was observed by SEM. PS Particle size and size distribution were analyzed by laser particle size analyzer. Results showed that it appeared coagulation in PS particles when the initiator dosage was more than 5.0 % of styrene mass or the di,;persion stabilizer dosage was less than 2 %, and PS microspheres, which had smoo.th surface and uniform spherical shape with particle size of 1. 612 btm and particle size distribution coefficient of 0. 357 ,could be obtained only at the optimized conditions as follows：styrene concentration was 10% ,AIBN dosage was 2.5% of styrene mass,PVP dosage was 5.5% of styrene mass,mass ratio of ethanol to water was 90：10,polymerization temperature was 70 ℃.