The use of silica gel varies according to the mechanism of vulcanization.
The mechanism of silicon rubber can be divided into three kinds: organic peroxide, the free radical crosslinking, condensation reaction, and additive reaction.
The adjuvant includes: reinforcing agent, vulcanization agent and some special auxiliary agent, need 5 ~ 6 component to be able to form a practical formula commonly.
(1) silicone rubber is high saturation of raw rubber, usually without sulphur vulcanization, adopt heat curing, heat curing by organic peroxide as curing agent, therefore, must not be found in the raw rubber can with peroxide decomposition product of the active material (such as the slot method of carbon black, some organic accelerator and stabilizer, etc.), otherwise it will affect the vulcanization.
(2) silicone products are commonly used in high temperature, and the combination of the agent should be stable at high temperature, and the inorganic oxide is usually used as a reinforcing agent.
(3) the cracking and rearrangement of siloxane is easily caused by the use of silicone rubber in the role of the polar chemical reagents, such as acid and alkali, causing the silicon rubber to reduce heat resistance.
Therefore, it is necessary to consider the acid alkalinity of the agent when choosing the synergist, and also consider the acid alkalinity of the oxide cracking product, so as not to affect the performance of the vulcanized rubber.
(silicone rubber is non-polar rubber)