Silicone rubber has excellent performance and is widely used in aerospace, electronic and electrical, automobile manufacturing, medical treatment, cosmetic surgery, baby products and other fields. In recent years, with the rapid development of science and technology, the application area of silicone rubber is further expanded, and the demand for high hardness silicone rubber is increasing. At present, the hardness of commercially available silicone rubber is only 70, which is far from meeting the requirements of use. With the increase of the hardness of silicone rubber, the mechanical properties and heat resistance of the silicone rubber decreased. When the hardness of the silicone rubber was greater than 70, the mechanical properties and heat resistance of the silicone rubber decreased more and the life of the silicone rubber could not be used or the service life was very short, which was very uneconomical. The nanoscale silica (VK-SP15S) produced by Xuancheng crystal can effectively improve the hardness of the silicone rubber and improve the mechanical and heat resistance of the silicone rubber.
Adding unmodified gaseous silica directly to silicon rubber, the hardness of the silicone rubber can be increased to 90, but it may lead to other mechanical properties, especially the deterioration of thermal stability. The gas phase silica particles are small, with an average diameter of 5~ 20 nm and a specific surface area of 200~400 m2/ g, which can be dispersed evenly in the silicone rubber and have a strong interaction with the silicone rubber molecules to increase the modulus and hardness of the silicone rubber, but the addition of excessive filler can lead to other mechanical properties such as tensile strength, tearing strength and tearing strength. The elongation at break decreases, which is caused by the presence of large amounts of hydroxyl groups on the surface of fumed silica.
After many experiments, the Xuancheng oil crystal nano SiO2 has successfully solved this problem. The surface modification of oil-gas phase nano-SiO2 (VK-SP15S) can effectively inhibit the surface hydroxyl effect of fumed silica. At the same time, the chemical combination of the hydroxyl group on the surface of the surface of the gas phase nano silica is formed, which can build a "bridge" between the gas phase nanoscale silica and the silicone rubber, which increases the interaction between the two and increases the combination of the rubber matrix and the filler particles, improves the mechanical properties of the high hardness silicone rubber, and also consumes the gas phase. The hydroxyl of silicon dioxide surface enhances the thermal stability of high hardness silicone rubber.
The application of VK-SP15S to silicone rubber can improve the hardness, mechanical properties and heat stability. The surface of VK-SP15S is modified by Pro oil, easy to add, easy to disperse, low viscosity, no dust and good operation. VK-SP15S can also be used in nonaqueous coatings, paints, glue, plastics, etc.
