one-component room temperature vulcanized silicone rubber
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The vulcanization reaction of one-component room temperature vulcanized silicone rubber is initiated by moisture in the air. The commonly used cross-linking agent is methyl triacetoxy silane. Its Si-OC bond is easily hydrolyzed. The acetoxy group combines with the hydrogen group in the water to form acetic acid, and the hydroxyl group in the water is moved to the original acetoxy group. In position, it becomes trihydroxymethylsilane. Trihydroxymethylsilane is extremely unstable and easily condenses with linear silicones whose end groups are hydroxyl groups to form a cross-chain structure. Usually, the raw silicone rubber containing silanol end groups and various compounding agents such as fillers, catalysts, cross-linking agents, etc. are packed into a sealed hose, squeezed out of the container during use, and vulcanized by the moisture in the air. Elastomers, at the same time emit low-molecular-weight substances.