种子溶胀法制备聚甲基丙烯酸酯类微球

以分散聚合法制得的单分散聚苯乙烯微球为种球,采用改进的两步种子溶胀法制备了粒度均一、高交联、多孔的聚甲基丙烯酸缩水甘油酯-乙二醇二甲基丙烯酸酯微球,并系统探索了稳定剂种类和浓度、活化剂用量、溶胀倍数、致孔剂的种类及比例对微球形态和粒径分布的影响,同时用光学显微镜、扫描电镜、红外光谱及高效液相色谱对微球进行了表征。结果表明,以2μm和4μm的聚苯乙烯微球为种球,当活化剂与种球质量比为4,溶胀倍数为20~40倍,致孔剂为体积比为6∶4的环己醇和甲苯混合溶剂,以质量分数0.2%的羟丙甲基纤维素(以整个体系质量计,下同)为稳定剂时可制得粒径5μm和10μm的单分散高交联多孔的聚甲基丙烯酸酯类微球。

Preparation of Methacrylate-based Microspheres by Seeded Swelling

The modified two-step seeded swelling polymerization was used to prepare monodisperse, high cross-linked and porous poly(glycidyl mthacrylate-co-ethylene dimethacrylate) (PGMA-EDMA) microspheres with polystyrene beads as the seeds, which were prepared by dispersion polymerization. Several factors including various stabilizer, ratio of activator and seeds, swelling multiples and different porogens were investigated to further enhance the characteristics of microspheres. Electron microscope, scanning electron microscope (SEM), and infrared spectroscopy (IR) and high performance liquid chromatography (HPLC) were used to test the properties of the microspheres. The results indicated that the monodisperse PGMA-EDMA microspheres with 5 um and 10 um could be obtained satisfactorily when the PS seeds were 2 um and 4 um, the ratio of activator and seeds was four times, the swelling multiples was 20-40 times, the volume ratio of cyclohexanol and toluene as porogens was 6/4, 0.2% hypromellose was the stabilizer.