Silicone rubber refers to the main chain from the silicon and oxygen atoms alternate composition, the silicon atom is usually connected with two organic groups of rubber. Ordinary silicone rubber is mainly composed of methyl and a small number of vinyl silicon oxide chain section. The introduction of phenyl can improve the resistance of silicone rubber to high and low temperature, and the introduction of tri-fluorine propyl and cyanide can improve the temperature resistance and oil resistance of silicone rubber. Silicone rubber is good at low temperature performance, generally under -55℃ can still work. After the introduction of phenyl, up to 73 ℃. Silicone rubber heat resistance is also very prominent, in 180 ℃ can be long-term work, slightly higher than 200 ℃ also can withstand a few weeks or longer still have elasticity, instantaneous can withstand 300 ℃ above the high temperature. The permeability of silicone rubber is good, and oxygen transmittance is the highest in synthetic polymers.
In addition, silicone rubber also has physiological inertia, does not cause coagulation of the outstanding characteristics, so in the medical field widely used. Silicone rubber sub-heat vulcanization type (high-temperature vulcanization silica gel HTV), room temperature vulcanization type (RTV), in which the RTV type is also divided into polycondensation reaction type and additive reaction type. High temperature silicone rubber is mainly used to make all kinds of silicone rubber products, and room temperature silicone rubber is mainly as a bonding agent, potting materials or mold use. Heat vulcanization type of the largest dosage, heat vulcanization type of methyl silicone rubber (MQ), Methyl vinyl silicone rubber (VMQ, dosage and product grade most), methyl vinyl phenyl silicone rubber pvmq (low temperature, radiation resistance), and other silicone rubber, fluorine silicone rubber.