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以4-乙烯基吡啶(4-VP)为功能单体、二乙烯基苯(DVB)和三羟甲基丙烷三甲基丙烯酸酯(TRIM)为混合交联剂,偶氮二异丁腈(AIBN)为引发剂,乙腈为反应介质,采用沉淀聚合法制备单分散聚合物微球.考察了共聚单体、溶剂、引发剂等聚合条件对聚合物微球粒径、分散性以及产率的影响.并用扫描电镜(SEM)、激光粒度分析仪、热重分析仪和红外光谱对微球进行了表征.结果表明,聚合物微球的表面形貌和产率可通过改变溶剂体积、单体/交联剂摩尔比和引发剂浓度等因素进行控制.降低乙腈溶液体积、增加DVB摩尔比例及交联剂摩尔比、可增加聚合物粒径及粒度分布均匀性,而聚合物产率随溶剂体积和DVB摩尔比增大而减小,随交联剂摩尔比和引发剂浓度的增加而增加.在最优条件下,即DVB和TRIM两者摩尔比4∶1,单体/交联剂摩尔比1∶5,乙腈用量为5.6 m L(单体和交联剂占介质体积的7%),引发剂浓度为2 wt%~6 wt%(占总反应单体的量)时,可获得形貌规则、产率较高的单分散poly(4-VP-co-DVB/TRIM)微球,微球平均粒径约4.02μm,粒径分布指数(U)为1.013.此外,热重分析结果显示,聚合微球于350℃时开始分解,600℃时失重率达84.9%.
Using 4-vinylpyridine (4-VP) as the functional monomer, divinylbenzene (DVB) and trimethylolpropane trimethacrylate (TRIM) AIBN) as initiator and acetonitrile as reaction medium, the monodispersed polymer microspheres were prepared by precipitation polymerization method.The effects of polymerization conditions such as comonomer, solvent and initiator on the particle size, dispersibility and yield of polymer microspheres The microspheres were characterized by scanning electron microscopy (SEM), laser particle size analyzer, thermogravimetric analysis and infrared spectroscopy.The results showed that the surface morphology and yield of polymer microspheres can be controlled by changing the volume of solvent, / Crosslinker molar ratio and initiator concentration and other factors to control the volume of acetonitrile solution to reduce the increase of DVB molar ratio and crosslinking agent molar ratio can increase the polymer particle size and particle size distribution uniformity, and the polymer yield with the volume of solvent And DVB molar ratio increased and decreased, with the crosslinking agent molar ratio and initiator concentration increases.Under optimum conditions, that the molar ratio of both DVB and TRIM 4: 1, monomer / crosslinking agent mole A ratio of 1: 5, an amount of acetonitrile of 5.6 mL (monomer and crosslinking agent account for 7% of the medium volume) The monodispersed poly (4-VP-co-DVB / TRIM) microspheres with regular morphology and high yield were obtained when the concentration of the initiator was 2 wt% ~ 6 wt% The average particle size of the microspheres was about 4.02μm and the particle size distribution index (U) was 1.013. In addition, the thermogravimetric analysis showed that the microspheres began to decompose at 350 ℃, and the weight loss rate reached 84.9% at 600 ℃.