Silicone rubber is generally a highly saturated structure with low vulcanization activity, so it cannot be vulcanized with sulfur. The most common and commonly used vulcanizing agent is organic peroxide. Silicone rubber can also undergo radiation vulcanization using high-energy radiation. The mechanism of radiation vulcanization is the same as that of peroxide vulcanization, both of which undergo free radical reactions to crosslink.

Dimethyl silicone rubber does not contain vinyl groups in its molecules and is a saturated rubber. It usually uses highly active peroxides as vulcanizing agents. The peroxide free radicals take away the hydrogen on the methyl group of silicone rubber to form macromolecular free radicals, which then combine to form cross-linked bonds, such as using benzoyl peroxide as a vulcanizing agent.

From the above reactions, it can be seen that silicone rubber containing vinyl groups can regenerate free radicals that can continue the reaction during vulcanization. Therefore, introducing a small amount of vinyl groups into silicone rubber can greatly improve the vulcanization activity, enhance the crosslinking efficiency of the vulcanizing agent, reduce the amount of peroxide used, and improve the performance of the product. Due to the fact that the initial free radicals that trigger crosslinking reactions are obtained from the decomposition of peroxides, increasing the amount of peroxides within a certain range can significantly improve the crosslinking degree of silicone rubber vulcanizates. This will lead to an increase in the tensile strength of the rubber material and improve its dynamic performance and compression deformation, but the tear resistance will decrease.

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