The influence of silica on rubber properties is mainly reflected in the following aspects:

Mechanical properties: The surface of silica black contains a large number of hydroxyl groups, which can form hydrogen bonds with the silicone rubber molecular chain, thus enhancing the interfacial bonding force between silica black and silicone rubber. Adding an appropriate amount of silica can significantly improve the mechanical properties of silicone rubber, such as elongation at break and tear strength. However, when the amount of silica added is too high, agglomeration between silicas is likely to occur, which will affect the mechanical properties of the material.

Thermal stability: As an inorganic substance, silica has non-flammable properties. Adding it to silicone rubber can reduce the combustible content in the composite material, thereby increasing the oxygen index of the material, that is, improving the thermal stability of the rubber.

Processability: The addition of silica may also affect the processability of silicone rubber. Excessively high filler content may reduce the processability and elasticity of silicone rubber and affect its overall performance.

In addition to the above main effects, silica can also improve the bonding properties between rubber and cord, which is crucial for tire manufacturing. White carbon black can also significantly improve the material's wear resistance, hardness, and reduce compression permanent deformation and thermal shrinkage. In addition, ultra-fine silica can also be used as a blown film release agent for plastic films, an additive for EVA plastic foaming materials, etc.

To sum up, the impact of silica on rubber properties is multifaceted, including improving mechanical properties, improving thermal stability, affecting processing performance, and enhancing adhesion with other materials. However, the specific impact needs to be comprehensively considered based on factors such as rubber type, silica addition amount, and processing technology.