Fumed silica is extremely important, one of the high-tech superfine inorganic new materials due to its small particle size, specific surface area is big, therefore the surface adsorption power, surface energy, high chemical purity, good dispersion performance, heat resistance, resistance has specific performance, with its excellent stability, reinforcing, thickening and thixotropic, and unique features in the field of the academic disciplines, Has an irreplaceable role. Today xiaobian and we will learn how to use fumed silica in silicon rubber.

Application of fumed silica in high temperature vulcanization (HTV) silicone rubber

The use of fumed silicon dioxide can be divided into organic silicon materials and other fields, in which the amount of organic silicon materials accounted for nearly 60% of the total amount of fumed silicon dioxide, silicone rubber is the most used in organic silicon materials, the amount of its addition can be up to 50%. In fumed silica HVT silicone rubber main reinforcement effect, because of the silicone rubber chain is very soft, weak interaction between chains, so without reinforcing the strength of silicone rubber is very low (less than 0.4 MPa), did not use value, must after reinforcement to application, and through fumed silica reinforcing silicone rubber, the strength of up to 40 times.

Effect of fumed silica on mechanical properties of HTV silicone rubber

The reinforcing effect of fumed silicon dioxide on HTV silicone rubber is affected by its particle size, comparative area and structure. Generally, the smaller the particle size, the higher the specific surface area, the higher the structure, the better the reinforcing effect, the higher the strength and hardness of vulcanized rubber. In addition, the amount of fumed silica and its dispersion in the matrix on the performance of the vulcanized adhesive is also very large, Figure 1 is the amount of fumed silica on the tensile strength of the vulcanized adhesive diagram. As can be seen from the figure, with the increase of the amount of fumed silica, the strength of vulcanized rubber increases, generally reaching the peak at 35-50 parts. On fumed of silica on silicon rubber reinforcing mechanism and model is also very much, is approved by the explanation is that the fumed free hydroxyl groups on the surface of the silica and silicon rubber molecules to form the physical or chemical combination, form of silicone rubber molecules adsorbed layer in the surface of silicon dioxide, a fumed silica and silicon rubber molecules of three-dimensional network structure, Thus, the deformation of silicone rubber molecular chain is effectively limited and its reinforcement effect is realized. The tearing strength of the vulcanized adhesive is similar to the tensile strength, which increases with the strengthening of the fumed silica, increases first with the increase of the amount of fumed silica, and then decreases slightly after reaching the peak value.