KH-570硅烷偶联剂表面改性微硅粉分散性研究

Surface Modification of Silica Fume Dispersivity with Silane Coupling Agent KH-570

采用KH-570硅烷偶联剂在酸性条件下对微硅粉(SF)表面进行了改性,通过控制改性时间和改性剂用量确定了最佳工艺参数,并对改性前后的微硅粉进行了表征,同时测定接枝改性样品表面的羟基数和吸油值,分析其改性效果。结果表明:改性后的微硅粉(KH570-SF)吸油值明显降低,表面羟基数急剧减少,KH-570硅烷偶联剂分子成功的以化学键的形式接枝在微硅粉表面,微硅粉团聚现象减少,分散性得到改善,同时对硅烷偶联剂改性微硅粉机理进行了探讨,结合热重和红外光谱分析表明,KH-570硅烷偶联剂主要通过与微硅粉颗粒表面的-OH形成氢键缔合而吸附到微硅粉颗粒表面上。

The surface of silica fume（ SF） was modified with silane coupling agent KH-570 under acidic conditions. The optimum process parameters were determined by controlling the modified time and the dosage of modifier. Silica fume before and after modification was characterized. The content of surface hydroxyl and oil absorption value of the silica fume were determined. The results show that the oil absorption value of the modified silica fume（ KH570-SF） decreased obviously and the content of surface hydroxyl decreased sharply. The molecular of coupling agent are bonded on the surface of silica fume by chemical bonds,reunion reduced and dispersion property improved of silica fume. Finally,the modification mechanism of silica fume with silane coupling agent KH-570 was studied. The combination of TG and FTIR showed that the KH-570 silane coupling agent was adsorbed onto the surface of the silica fume mainly by forming a hydrogen bond with the-OH of the surface of the silica fume.