Structural Control in Silicone Rubber Reinforced Silicone Ru
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Summary：
White carbon, especially fumed silica, is the best reinforcing agent for silicone rubber, but there is a problem of hardening the compound, commonly referred to as
White carbon, especially fumed silica, is the best reinforcing agent for silicone rubber, but there is a problem of hardening the compound, commonly referred to as the "structuring effect." The structure of the plastic material with the extension of the parking time increases, and even serious enough to return to refining, scrapped. There are two explanations for this. One is that the terminal hydroxyl groups of the silicone rubber condense with the hydroxyl groups on the surface of the silica. On the other hand, it is believed that the siloxanes of the silicone rubber form hydrogen bonds with the hydroxyl groups on the surface of the silica. There are two ways to prevent the structuring. One is to add some substances that can react with hydroxyl groups on the surface of silica, such as hydroxy silicone oil, diphenyl silicon glycol, silazane and so on. When diphenylsilanediol is used, the mixture should be treated at 160-200 ° C for 0.5-1 h after mixing. This prevents the silica-filled silicone from being structured. Another approach is to pre-silica surface modification, first remove part of the surface hydroxyl, the fundamental elimination of the structure.
