细乳液聚合法制备磁性复合微球及其表征

在制备超细Fe3O4 磁性粒子的基础上 ,以 3种低分子量聚合物Disperbyk 1 0 6、Disperbyk 1 0 8和Disperbyk 1 1 1为Fe3O4 微粒在单体相中的分散稳定剂 ,采用细乳液聚合法制备了平均粒径为 3 40nm的PS Fe3O4 磁性复合微球 .详细研究了分散剂种类对细乳液聚合制备磁性复合微球的影响 ,并采用XRD、TGA和TEM等手段对磁性复合微球的形态、结构及磁响应性等进行了表征 .实验结果证明分散剂的选择对磁性复合微球的成功制备起着至关重要的作用 ,兼具酸性和碱性功能基的分散剂Disperbyk 1 0 6具有更好的分散和稳定效果 .TEM结果表明 ,所制备的复合微球具有一些缺陷 ,而缺陷处往往是Fe3O4 磁性粒子聚集的地方

PREPARATION OF MAGNETIC COMPOSITE MICROSPHERES BY MINIEMULSION POLYMERIZATION AND THEIR CHARACTERIZATION

Submicron polystyrene/magnetite (PS/Fe 3O 4) composite microspheres were prepared by miniemulsion polymerization by using three kinds of low molecular weight polymer,Disperbyk-106,Disperbyk-108 and Disperbyk-111,as dispersant for magnetite particles and styrene.The effects of dispersants on the miniemulsion polymerization were discussed in detail,which showed that the addition of dispersant had a crucial effect on the preparation of the composite microspheres.Disperbyk-106,which contains both acid and basic groups,has a better effect on the improvement of the interface between magnetite particles and styrene.X-ray powder diffraction (XRD),thermogravimetric analysis (TGA) and transmission electron microscopy (TEM) were conducted to character the magnetite particles and PS/Fe 3O 4 composite microspheres.The average size of the composite microspheres is 340 nm and the magnetite content of the composite microspheres is around 8%.The XRD patterns showed that the magnetite particles preserve their crystal structure during the miniemulsion polymerization.The TEM observation revealed that magnetite particles distributed unevenly in the composite microspheres and there were some defects on the microspheres where magnetite particles agglomerated.