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采用超声波改进的二步种子溶胀法制备粒径2.4～9μm的多孔聚苯乙烯-二乙烯苯微球,单分散的聚苯乙烯微球由分散聚合制备并以其作为种球。论文考察了种球类型、超声分散时间、种球和溶胀剂以及交联单体比率等因素对多孔微球形貌及孔结构的影响,并采用扫描电镜、BET等手段对微球性能进行了表征。研究发现超声辅助分散的引入可使产物的粒径分布更窄并将第一步溶胀时间由传统的24h缩短至10h。实验结果表明:种球的单分散性对最终产物的形貌有决定性影响,它的任何形貌缺陷都将在最终产物中被扩大;随着溶胀剂/种球比率和交联单体/种球比率的增加,最终产物的粒径和比表面积增大,孔径减小。以对苯二酚为模型组分,考察其在制得的多孔微球上的缓释行为,发现制得的多孔聚合物微球在用作化妆品活性组分载体时,表现出良好的缓释性能。
Porous polystyrene-divinylbenzene microspheres with a particle size of 2.4 ~ 9μm were prepared by ultrasonic two-step seed swelling method. Monodisperse polystyrene microspheres were prepared by dispersion polymerization and used as bulbs. The effects of bulb type, ultrasonic dispersion time, bulbs and swelling agents and the ratio of crosslinking monomers on the morphology and pore structure of porous microspheres were investigated. The microspheres were characterized by scanning electron microscopy (SEM) and BET Characterization. The study found that the introduction of ultrasonic assisted dispersion can make the particle size distribution of the product narrower and shorten the first step swelling time from the traditional 24h to 10h. The experimental results show that the monodispersity of the bulbs has a decisive influence on the morphology of the final product, and any morphological defects of the bulbs will be enlarged in the final product. With the swelling agent / bulblet ratio and the crosslinking monomer / species As the ball ratio increases, the particle size and specific surface area of the final product increase, and the pore size decreases. Hydroquinone was used as a model component to investigate its sustained-release behavior on the prepared porous microspheres. It was found that the prepared porous polymer microspheres exhibited good sustained release when used as a carrier for cosmetic active components performance.