Application of Gaseous Silica Powder in High Temperature and Room Temperature Vulcanized Silicone Rubber

1. Application of fumed silica powder in high temperature vulcanized silicone rubber

The use of fumed silica powder can be divided into organic silicon materials and other fields, and the amount of organic silicon materials accounts for nearly 60% of the total amount of fumed silica powder. Silicone on rubber is the material that uses fumed silica powder most among the organic silicon materials, and its addition amount can be as high as 50% or more.

Fumed silica powder mainly acts as a reinforcement in high-temperature vulcanized silicone rubber. Since the molecular chain of silicone rubber is very flexible and the interaction between the chains is weak, the strength of unreinforced silicone rubber is very low (no more than 0.4MPa) , and it has no use value and must be reinforced before it can be applied. However, the strength of silicone rubber reinforced with fumed silica powder can be increased by up to 40 times.

2. Application of fumed silica powder in room temperature vulcanized silicone rubber

Room temperature vulcanized silicone rubber is divided into two categories in terms of product form: single-component (RTV-1) and two-component (RTV-2); from the vulcanization mechanism, it is further divided into two systems, condensation type and addition molding.

Various forms of room temperature vulcanized silicone rubber need to be reinforced with fillers to be useful. At present, fumed silica powder is the most used and most effective vulcanized silicone rubber reinforcing filler.

As room temperature vulcanized silicone rubber is generally used as a sealing material for pouring, caulking, coating, etc., in order to maintain the viscosity and fluidity before vulcanization, the amount of fumed silica powder added is generally less than that of high-temperature vulcanized silicone rubber, and it is often used with the combination with other reinforcements and semi-reinforced fillers for easy construction operations.