When silica gel is burned, it will not ignite an open flame and is white smoke, gray is white, rubber is black smoke, gray is black, and it smells very bad.

Rubber is divided into natural rubber and synthetic rubber. The structure of natural rubber is a high polymer of isoprene, and synthetic rubber such as cis-1,4-polybutadiene rubber, chloroprene rubber, styrene butadiene rubber, etc. The crosslinked rubber has the ability of rapid recovery when deformed by external force, and has good physical and mechanical properties and chemical stability.

Silicone rubber is mainly composed of linear polysiloxane with high molar mass.

Due to the fact that Si-O-Si bonds are the basic bond type of silicone rubber, with silicon atoms mainly connecting methyl groups and introducing a very small amount of unsaturated groups on the side chains. The intermolecular force is small, and the molecules are in a helical structure. The methyl groups are arranged outward and can rotate freely. Therefore, after vulcanization, silicone rubber has excellent high and low temperature resistance -100-315 ℃, weather resistance, hydrophobicity, electrical insulation, physiological inertia, and other characteristics. It is widely used in national defense, military industry, medical and health It has been widely used in industrial and agricultural production and people's daily lives.