2、 Methyl vinyl silicone rubber






Due to the introduction of a small amount of vinyl into the macromolecular structure of silicone rubber can greatly improve the vulcanization processing performance of silicone rubber, most of the silicone rubber currently used contains vinyl. Methyl vinyl silicone rubber is the most common kind of silicone rubber, and it plays a leading role in the production of silicone rubber at home and abroad. Due to the introduction of partial unsaturated vinyl in the side chain, its processability and physical mechanical properties are better than those of two base silicone rubber. In addition to its general properties of dimethylsilicone rubber, It also has a wide range of use temperature, and can keep good elasticity in the range of - 60 ~ 260 ℃. It is easier to vulcanize than dimethylsilicone rubber, with smaller compression permanent deformation, better solvent resistance expansion, high-pressure steam resistance stability and excellent cold resistance. Moreover, because of the use of peroxide with lower activity for vulcanization, it reduces the generation of vulcanization Weak points of bubble and rubber stability. Therefore, methyl vinyl silicone rubber is generally used to make products with large thickness. Methyl vinyl silicone rubber is the most widely used type of silicone rubber. In recent years, a variety of silicone rubber with high performance and special use are emerging, most of which are based on vinyl silicone rubber, such as high-strength silicone rubber, low compression permanent deformation silicone rubber, no post vulcanization silicone rubber, heat-resistant conductive silicone rubber and medical silicone rubber. In aviation industry, methyl vinyl silicone rubber is widely used as gasket, sealing material and protective layer of fragile and shockproof parts; in electrical industry, it can be used as advanced insulating material such as electronic components, dynamic sealing ring of high temperature resistance potentiometer and sealing ring of underground long-distance communication equipment; in medicine, because of its small physiological response to human body and non-toxic, it is used as Plastic surgery, artificial heart valves, blood vessels, etc.






3、 Methyl phenyl vinyl silicone rubber






Methyl phenyl vinyl silicone rubber is a product made by introducing methyl phenyl silicone or diphenyl silicone into the molecular chain of methyl vinyl silicone rubber.






The introduction of phenyl on the side group of polysiloxane will destroy the regularity of the structure of dimethylsiloxane, greatly reduce the crystallization temperature of the polymer, and expand the low-temperature application range of the polymer material. Therefore, in addition to the small compression set, wide temperature range, oxidation resistance, weather resistance, shockproof, moisture-proof and good electrical insulation properties, methyl phenyl vinyl silicone rubber also has excellent low temperature resistance, ablation resistance and radiation resistance. These properties vary with the amount of phenyl in the chain, Generally speaking, when the phenyl content (the ratio of phenyl to silicon atom) is 5-10%, it is called low phenyl silicone rubber. It has unique cold resistance and can keep the elasticity of rubber at - 70-100 ℃. It is the best one of all rubber at medium and low temperature. In addition, it has the advantages of methyl vinyl silicone rubber and the cost is not high, so it has the trend of replacing methyl vinyl silicone rubber. When the content of benzene is 20-40%, the medium phenyl silicone rubber has both the advantages of methyl vinyl silicone rubber and the cost is not high, so it has the trend of replacing methyl vinyl silicone rubber. When the content of benzene is 20-40%, it is called medium phenyl silicone rubber. It has excellent fire resistance, and it can extinguish itself in case of fire. It is called high phenyl silicone rubber when the content of phenyl is 40-50%. It has excellent radiation resistance, and the resistance to γ - ray is 1xi08 roentgen. Generally speaking, with the increase of phenyl content, the rigidity of silicone rubber molecular chain increases gradually, and the low temperature resistance of silicone rubber decreases gradually, but with the increase of phenyl content, the flame resistance and radiation resistance of vulcanizate are improved.






Methyl phenyl vinyl silicone rubber is one of the important materials in aerospace industry, cutting-edge technology and other sectors of national economy. It can be used to make all kinds of molded and extruded products for cold resistant rubber in aviation industry and for sealing rings, pads, pipes and bars used in ablation, heat aging or radiation resistant parts.