The side groups of the main chain of the silicon rubber can be methyl, ethyl, vinyl, phenyl, three fluorine group, etc.. The most commonly used is the methyl group, which can also lead to other groups to improve the processing performance and other properties. Therefore, according to the different side group and compound recipe, can get the various uses of silicone rubber, generally can be divided for the following several types: common type (including methyl and vinyl), high temperature and low temperature type (including phenyl, Jia Jihe vinyl, low compression permanent deformation (including methyl and vinyl), low shrinkage (to volatile) and solvent (fluorosilicone rubber). Here are several important types of silicone rubber.

1 methyl vinyl silicone rubber
Because of the silicone rubber high molecular structure into a small amount of ethylene radicals silicone rubber vulcanization processing performance is greatly improved, so in the current application of silicone rubber, most of them contain vinyl. Methyl vinyl silicone rubber is the most common kind of silicone rubber, and it is the dominant position in the production of silicone rubber at home and abroad. Due to the introduction of some unsaturated vinyl groups on the side chain, the processing performance and the physical mechanical properties of the unsaturated vinyl group are better than those of the two base silicone rubber. It besides have the general characteristics of the dimethyl silicone rubber, but also has a wide operating temperature range, can keep good elasticity in the range of 60 to 260 C, it than dimethyl silicone rubber vulcanization easy, with small compression permanent deformation, good solvent resistance of expansion and stability of high pressure steam resistant and excellent tolerance to cold and because of the lower activity of peroxide vulcanized, thereby reducing the sulfide produced poor stability of bubbles and rubber weakness. Therefore, the general use of methyl vinyl silicone rubber can be made of the larger thickness of the products. Methyl vinyl silicone rubber is the most widely used in silicone rubber varieties, are emerging constantly in recent years, a variety of high performance and special purpose of silicone rubber, mostly with vinyl silicone rubber based adhesive, such as high strength silicone rubber, low compression permanent deformation of silicon rubber, no vulcanized silicone rubber, heat conductive silicone rubber and medical silicone rubber etc.. Methyl vinyl silicone rubber in the aviation industry, widely used as protective layer gaskets, sealing materials and fragile, shockproof parts; in the electrical industry can be as electronic components, and other advanced insulation, resistance to high temperature of a potentiometer dynamic sealing ring, sealing ring for underground long-distance communication equipment; in medicine, due to the physiological reaction of methyl vinyl silicone rubber on the human body is small, non-toxic, so as plastic surgery, artificial heart valves, vessels etc..
Two 2 methyl silicone rubber
Dimethyl silicone rubber is put into commercial production of the earliest a silicone rubber can be in the range of 60 to 200 DEG C to keep good elasticity, resistance, good ageing resistance, excellent electrical insulation performance and moisture, shock and physiological inert characteristics. Dimethyl silicone rubber is mainly used for coating fabrics, also can be made into various extrusion and rolling products for Electromechanical, aerospace, automotive and medical industries. However, due to the low sulfur activity of two methyl silicone rubber, when used in the manufacture of thick articles, the curing is difficult, the inner layer is easy to foam and high temperature compression deformation is large, so it has been replaced by methyl vinyl silicone rubber.
3 methyl phenyl vinyl silicone rubber
Methyl phenyl vinyl silicone rubber is in the molecular chain of methyl vinyl silicone rubber into methyl phenyl silicone link or diphenyl silicon oxygen chains and products. Introduction in the polysiloxane with side groups on the phenyl, due to the destruction of the regularity of the dimethyl siloxane structure, greatly reducing the crystallization temperature of polymers, expanded the application temperature range of the polymer materials. Therefore, Ben Ji methyl vinyl silicone rubber with methyl vinyl silicone rubber all compression permanent deformation small, wide temperature range, oxidation resistance, weatherability, shockproof, moisture-proof and good electrical insulation properties, also has excellent temperature resistance, ablation resistance and radiation resistance properties. These properties vary with. Ben Ji was in the molecular chain of different content (in general, Ben Ji Ben Ji and the silicon atom ratio) in 5 to 10% when Ben Ji said the low silicon rubber, it has a unique cold resistance, ranging from -70 to -100 DEG C can still maintain the elasticity of rubber, is the best one in the low temperature performance of rubber, and it with methyl vinyl silicone rubber has the advantages of and the cost is not high, so much to replace the trend of methyl vinyl silicone rubber. Phenyl content of 20 ~ 40%, said the phenyl silicone rubber, it has excellent combustion characteristics, once the fire can be extinguished. Phenyl content in 40 ~ 50% called high phenyl silicone rubber, it has excellent radiation resistance, resistance to gamma ray 1xI08 roentgen. In general, with increasing content of phenyl, gradually increasing the rigidity of the molecular chain of silicon rubber, silicone rubber cold resistant properties gradually decreased, but increased with the content of phenyl and improve the vulcanizate of flame resistance and radiation resistance. Methyl phenyl vinyl silicone rubber is one of important materials for the other departments of the aerospace industry, cutting-edge technology and national economy, and can be used for manufacturing various molding and extrusion products used in aviation industry of cold resistant rubber and for ablation resistance, heat aging or resistant to radiation parts of the sealing ring, mats, tubes and rods and other.
4 silicone rubber
Because the side chain of the polymer molecule contains the strong polar group of the beta or gamma, the molecular chain is greatly increased, and the oil resistance and solvent resistance are improved. At the same time, due to the introduction of a certain amount of the alkyl group, the structure of the polymer has been destroyed, and the cold resistance has been greatly improved. The type and content of alkyl nitriles and on the performance influence, such as containing 7.5 mol% gamma nitrile propyl silicone rubber, low temperature performance and low phenyl silicone rubber similar -114.5 deg.c and the glass transition temperature, oil resistance than phenyl silicone rubber. With gamma - propyl nitrile content increased to 33 ~ 50 mol%, cold resistance decreased, oil resistance improved. With the beta gamma - propyl ethyl nitrile instead of nitrile nitrile rubber can improve the heat resistance, can withstand 250 degrees hot air aging. Nitrile silicone rubber the main advantage is the oil resistant and bath agent performance excellent, in 60 ~ 180 DEG C range to maintain flexibility, therefore, can be made of oil resistant rubber products for the aviation industry, automobile industry and oil industry, as a high performance aircraft environmental sealant and the oil tank sealant, in more than 54 DEG to 200 DEG C can remain sealed. Nitrile silicone

5 phenyl silicone rubber
Phenyl silicone rubber is mainly characterized in having excellent radiation resistance, radiation resistance performance is 10 to 15 times higher than the general methyl vinyl silicone rubber, is 5 ~ 10 times higher than that of the phenyl silicone rubber, therefore, can be used in aerospace industry, atomic energy industry and nuclear reactors as resistant to radiation cable, a sheath, a gasket and a heat shrinkable tubes and.
6 silicone rubber
The main advantage of nitrogen and silicon rubber is with excellent thermal stability. In 430 ~ 480 DEG C does not decompose, and some even ability or above 500 DEG C high temperature. The outstanding weakness of silicone rubber is the poor hydrolytic stability, which was once thought to have no future. It was found that the polymer has a good thermal stability in the introduction of the ring two in the main chain. In the air, the elastic body of the 570 silicon nitride containing ring two is modified by silicon, which is heated to 425 degrees C without loss of weight, and the weight loss is only 10%, and has better hydrolysis stability.
7 fluorine silicone rubber
Fluorosilicone rubber refers to gamma three fluorine methyl polysiloxane. Fluorosilicone rubber has excellent resistance to chemicals and solvent resistance and oil resistance, this kind of silicon rubber in the non solvent polar expansion rate, good cold resistance and thermal stability, anti fire or, so in aircraft, rockets, missiles, space flight, petroleum chemical used as fuel oil and lubricating oil contact tube, a gasket, a sealing ring, a fuel tank in the village can also be used in the manufacture of corrosion clothes, gloves and coatings, adhesives and.
8 ethyl silicone rubber
In side chain polysiloxane was introduced for the synthesis of ethyl diethyl silicone rubber, its outstanding performance is particularly good cold resistance, cold resistance is better than that of dimethyl silicone rubber and the methyl vinyl silicone rubber. The higher the content of ethyl, the better the cold resistance. But the reaction activity of the ethyl group is larger than that of the methyl group, so the heat resistance decreases with the increasing of the ethyl content. As ethyl silicone rubber used at low temperature, with two ethyl silicone chain in the polymer was 8 mol%.