Silicone rubber is a kind of rubber whose main chain is composed of silicon and oxygen atoms alternately. Silicon atoms are usually connected with two organic groups. Ordinary silicone rubber is mainly composed of silicone oxygen chains containing methyl group and a small amount of vinyl group. The introduction of phenyl can improve the high and low temperature resistance of silicone rubber, while the introduction of trifluoropropyl and cyanogen can improve the temperature and oil resistance of silicone rubber. Silicone rubber has good low temperature resistance and can work at - 55 C. When phenyl is introduced, the temperature can reach - 73 C. The thermal resistance of silicone rubber is also outstanding. It can work for a long time at 180 C, and can withstand several weeks or longer elasticity at slightly higher than 200 C. It can withstand high temperature above 300 C instantaneously. Silicone rubber has good air permeability, and oxygen permeability is the highest in synthetic polymers. In addition, silicone rubber has the outstanding characteristics of physiological inertia and does not cause coagulation, so it is widely used in the medical field.

classification
According to its vulcanization mechanism, silicone rubber can be divided into heat vulcanization type (HTV) and room temperature vulcanization type (RTV), of which room temperature vulcanization type can be divided into condensation reaction type and addition reaction type. High temperature silicone rubber is mainly used to manufacture various silicone rubber products, while room temperature silicone rubber is mainly used as adhesives, filling materials or moulds. Thermal vulcanization type is the most widely used type. Thermal vulcanization type can be divided into methyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl vinyl phenyl silicone rubber (PVMQ) (low temperature and radiation resistance), and other kinds of silicone rubber, such as eye silicone rubber and fluorosilicone rubber.