Room temperature vulcanization (RTV) silicone rubber is divided into two types of single-component (RTV-1) and two-component (RTV-2) in terms of product form; from the vulcanization mechanism, it is divided into two systems: condensation and addition. . Various forms of room temperature vulcanized silicone rubber need to be reinforced with fillers to be of value. At present, fumed silica is the most used and most effective RTV silicone rubber reinforced filler. Since RTV silicone rubber is generally used as a sealing material for casting, caulking, coating, etc., in order to maintain the viscosity and fluidity before vulcanization, the amount of fumed silica is generally much less than that of high temperature vulcanized silicone rubber, and it is often used with other fillers. Strong and semi-reinforcing fillers are used together to facilitate construction operations.

RTV silicone rubber generally uses fumed silica with a relatively low specific surface area as a filler. The unreinforced silicone rubber becomes brittle after vulcanization. After adding fumed silica for reinforcement, the hardness of the silicone rubber increases with the increase in the amount of silica added.

When adding fumed silica to RTV silicone rubber, one must pay attention to the degree of dispersion in the polymer. Under the same dispersion conditions, fumed silica products with a large specific surface area generally have better transparency.