What influence does fumed silica have on the performance of silicone rubber tube?

The amount of fumed silica in silicone rubber tube is very large, especially in hot vulcanized silicone rubber, and its addition can reach 40% ~ 50%. Although precipitated silica can also be used as a reinforcing filler for silicone rubber, the electrical properties and heat resistance of silicone rubber filled with precipitated silica are not as good as those filled with fumed silica due to its high water absorption and impurity content. Therefore, fumed silica occupies a dominant position in this application field.

Fumed silica is an amorphous silica product prepared by hydrolysis of halosilanes at high temperature by hydrogen-oxygen flame. Its primary particle size is between 7 and 7～40nrn, its specific surface area is generally greater than 1002/g, and its SO2 content is not less than 99.8%. It is an extremely important inorganic nano-powder material. Because of its excellent stability, reinforcement, thickening and thixotropy, it has been widely used in rubber, plastics, electronics, coatings, adhesives and sealants.