功能高分子微球研究分散聚合法合成μ级聚苯乙烯微球

Study on Functional Polymeric Microspheres Preparation of μ-size Polystyrene Microspheres by Dispersion Polymerization

微米级聚苯乙烯微球广泛用于临床分析、生物医学、胶体研究等领城,亦可作为电子显微镜、光散射、沉降法等测定微小物体绝对长度的基准物、色谱柱填料等。用分散聚合法可以制得微米级单分散聚苯乙烯微球。本文通过对分散聚合条件和配方的研究,以水和醇为分散介质,分子量4000的聚乙二醇为稳定剂,过氧化苯甲酰为引发剂,合成了粒径为3至4μm的单分散聚苯乙烯微球。在分散聚合体系中,随着有机溶剂、单体、引发剂等用量的增加,胶乳粒径增大,粒径分布变宽。随着稳定剂、表面张力调节剂等用量的增加,胶乳粒径减小,粒径分布变窄。有机溶剂种类改变以及聚合反应温度变化,胶乳粒径也发生变化。

μ-size polystyrene microspheres are widely used in the fields of biology medicine and colloidal science. The microspheres are prepared by the dispersion polmerization f styrene in alcohol/water nixtures containing polyethylene glycol as steric stabilizer. The microspheres size and their size distribution appear to be highly dependent of various conditions. Increasing styrene concen tration, alcohol/water ratio and initiator concentration, the microspheres size increses, their uniformity decreases. Increasing stabilizer amount and n-Octyl alcohol concentration, the microspheres size decreases, their uniformity increases. Alcohol type and temperature have also effects on microspheres size and uniformity by controlling these factors the monodisperse microspheres up to 4μ can be prepared.