Silicon rubber is ageing-resistant, high and low temperature resistant and electricity-insulated. However, the molecular chain of silicon rubber is soft, the interaction force is weak, so silicon rubber needs to be reinforced before actual usage.
Fume silica is an ideal reinforcing agent for silicon rubber. The strengthening is fundamentally brought about by silanol groups being interacted with or Si-methyl bonds being radically cleaved into the polymer. The surface silanol groups (Si-OH) of fumed silica react with silicone rubber macromolecule ,then generates a silicon rubber molecular adsorption layer on the surface of silica, then a three-dimensional network structure is formed. This structure effectively limits the deformation of the silicone rubber molecular chain, thereby achieving the reinforcing effect.