Foam silicone rubber is a sponge elastomer with a hole formed by condensation and hydroxyl terminated silicon raw rubber as raw material, hydroxyl hydrogen silicone oil as foaming agent and vinyl platinum complex as catalyst (heating catalyst two butyl two lauric acid tin). In order to improve the quality of foam, some other components, such as silicone oil, should be added to produce more gas during the vulcanization process. The addition of two phenyl siloxane can not only control the structure of the foam, but also control the viscosity of the rubber during storage, but it can not be used too much, otherwise it will affect the electrical properties of the foam. In order to improve the physical and mechanical properties of the foam, transparent silicone rubber can also be added. The amount of vinyl complex of the catalyst chloro platinic acid can not be too much, and the operation is convenient. Otherwise, the viscosity will increase, which will not be beneficial to the operation. When the amount of catalyst is insufficient, the vulcanization is incomplete, the surface of the foam is sticky, elastic is not good, soft and plastic, and the strength is poor.

Foam silicone rubber is liquid before vulcanization and suitable for potting material. The foam after vulcanization can be used for a long time at -60~159 C, and after 150 or 72 hours aging or 60 to ten 70 C ten times, the foam remains the same. Foam silicone rubber is an ideal lightweight material because of its high thermal stability, good heat insulation, insulation, moisture resistance and shock resistance, especially in high frequency. It is used for the protection of "three preventions". In addition, it can be used as filling material for insulation sandwich, floating material in salt spray atmosphere and sealing material. Foam silicone rubber can also be used as a filling, repairing and material for orthopedic surgery in medicine. In order to meet the fire protection requirements of transmission lines, the American anti Corelle company has developed a flame retardant RTV foam silicone rubber DC3-6548. The foam silicone rubber is mainly used for fireproofing and sealing of wires and cables passing through holes (such as roofs, walls, buildings, etc.). Its flame retardancy is very good. Its limit oxygen index reaches 39 (most plastic limit oxygen index is only 20), and its service life is as long as 50 years. At present, the flame-retardant room temperature vulcanized foam silicone rubber has been widely used in nuclear power plants, electronic computer centers, offshore oil extraction devices and other harsh environmental conditions, or places with high fire safety requirements.