微米级单分散性聚苯乙烯微球的制备和影响微球粒径及其分布的因素

Preparation of Micron-Sized Monodispersed Polystyrene Microsphere:Influencing Factors of Its Size and Distribution

苯乙烯（St）为单体、偶氮二异丁腈（AIBN）为引发剂、聚乙烯基吡咯烷酮（PVP）为分散剂，在乙醇-水反应介质中，采用分散聚合法制备了粒度均一、单分散性好的聚苯乙烯（PS）微球。考察了初始单体含量、引发剂用量、分散剂用量、反应温度和反应介质的组成等因素对PS微球的粒径及其分布、PS固含量和St转化率的影响。实验结果表明，在St加入量为15～25mL、AIBN和PVP用量分别为St质量的1．00％～2．00％和10．00％～15．00％、H，O加入量为0～10mL（固定介质的总体积为100mL）、反应温度70℃、反应时间24h、搅拌转速130r／min的较佳聚合条件下，制备了粒径为1．5～3．0μm、分散系数为0．020～0．100、St转化率最高达99．53％的球形、均匀且表面光滑的单分散性PS微球。

The micron-sized monodispersed polystyrene （PS） microspheres were prepared by dispersion polymerization of styrene （St） in ethanol-H2O medium with polyvinylpyrrolidone （PVP） as dispersing agent and 2,2-azobisisobutyronitrile（AlBN） as initiator. The effects of monomer concentration, initiator dosage and dispersant dosage, reaction temperature and reaction media composition on St conversion, PS solid content, microsphere size and size distribution were investigated. Average size of prepared microspheres ranged from 1.5 to 3.0 μm with dispersion coefficient from 0. 020 to 0. 100. The optimal conditions to achieve uniform, smooth-faced monodispersed PS microspheres were： St 15 -25 mL, AIBN dosage 1.00% -2.00% （based on mass of St）, PVP dosage 10.00% - 15.00% （based on mass of St）, H2O dosage 0 - 10 mL （in fixed total amount of media 100 mL）, reaction temperature 70 ℃, reaction time 24 h and stirring speed 130 r/min. The highest St conversion reached 99.53 %.