Silica plays a vital role in the production of silicone rubber, and its unique properties significantly improve the overall performance of silicone rubber.


Silica is an amorphous silica material with a high specific surface area, which can be divided into fumed silica and precipitated silica according to the production method.In the production of silicone rubber, silica is mainly used as a reinforcing filler.


Its high specific surface area and rich surface hydroxyl groups enable it to form a strong interaction with the molecular chain of silicone rubber, significantly improving the tensile strength, tear strength and hardness of silicone rubber.For example, fumed silica has a particularly prominent reinforcing effect due to its small particle size and large specific surface area, which can increase the tensile strength of silicone rubber to more than 17.0 MPa and the elongation at break to more than 675%.


The addition of silica can also improve the wear resistance and weather resistance of silicone rubber.Its porous structure can fill the voids in the silicone rubber matrix, reducing the stress concentration inside the material, thereby reducing the wear rate.At the same time, the hydroxyl groups on the surface of silica can adsorb harmful substances and oxygen in the environment, form a protective layer, and effectively delay the aging process of silicone rubber.


This characteristic allows silicone rubber to maintain stable performance and extend its service life in outdoor or harsh environments.


In addition, silica also has a positive impact on the processing performance of silicone rubber.Its good dispersion can reduce energy consumption in the mixing process and improve production efficiency.However, the hydrophilicity of silica may lead to poor compatibility with the silicone rubber matrix, so it is often necessary to use silane coupling agents for surface modification to convert it into hydrophobicity to enhance the interfacial binding force with silicone rubber.


The modified silica can not only improve the reinforcing effect, but also improve the fluidity and molding properties of silicone rubber.


In the application field, silica-reinforced silicone rubber is widely used in aerospace, electronic appliances, medical devices and other industries.For example, in the aerospace field, silicone rubber seals need to have excellent high temperature resistance and aging resistance. The addition of silica can significantly improve their reliability.；


In the field of electronic and electrical appliances, silicone rubber insulation materials need to have good thermal conductivity and electrical insulation. The thermal conductivity of silica can effectively improve the heat dissipation effect, and its high resistivity can ensure electrical safety.