日韩精品久久久毛片一区二区,国产第一福利精品导航,亚洲欧美日韩国产色另类,99久久综合狠狠综合久久aⅴ,色www永久高清,欧美精品一区二区三区中文字幕 ,国产精品亚洲第一区广西莫菁,国产青青草视频,极品美女久久久久久久久久久,国产在线欧美日韩一区二区

Silicone polymer is linear high-molecular compound based on Si - O - Si bond chain, with side chains of methyl, phenyl, vinyl, hydroxyl, hydrogen and other organic groups. By different degree of polymerization and appearance, silicone polymers can be divided into: (1) silicone fluid. With low molecular weight, it is a kind of liquid, main products are OH Polymer, Polydimethyl silicone oil, vinyl silicone oil,methylhydrogen silicone oil, Silicone liquids are used to produce liquid silicone rubbers, sealants, emulsions. (2) silicone gum. With high molecular weight, silicone rubber is semi-solid. Methyl vinyl silicone gum and methyl phenyl silicone gum are main products, which is the raw material of high temperature vulcanized silicone rubbers