Fumed silica is a very effective reinforcing filler for RTV silicone rubber and can significantly increase its strength. On the one hand, this is due to the small size effect of fumed silica particles and the large specific surface area; On the other hand, because its surface contains a lot of silicon hydroxyl, the particles can form a network structure through hydrogen bonding and van der Waals force, while the silica particles also have a strong interaction with polysiloxane molecules, improving the interface bond. The smaller the particle size of fumed silica, the larger the specific surface area, the larger the contact surface between the particles and the rubber, the more binding points, the better the reinforcing performance of RTV silicone rubber, the tensile strength, tearing strength, wear resistance and hardness of vulcanized rubber are also high, but at the same time, the dispersion becomes very difficult, the elasticity decreases, and the processing performance deteriorates. RTV silicone rubber generally uses fumed silica with a relatively low specific surface area (less than 200m2/g) as a filler [16]. The unreinforced silicone rubber is brittle after vulcanization, and the hardness of the silicone rubber increases with the addition of silica.

HTV Phenyl Silicone rubber, plz check MY 3120