Treatment method of fumed silica surface

The surface of fumed silica can be well treated by henamethyldisilazane(HMDZ) with auxilliary surface treatment agent. The treated fumed silica is suitable for the preparation of two-part RTV silicone rubber. The effects of the ratio of fumed silica and HMDZ,reaction temperature and reaction time on the performance of two-part RTV silicone rubber were discussed. The optimum reaction conditions would be that 100 portion fumed silica was treated by 17 portion HMDZ at 120 ℃,above 60 min. RTV silicone rubber,which was treated by fumed silica has good mechanical and operating performance.