4. Fluorine silicone silica gel refers to γ- trifluoropropyl methyl polysiloxane. Fluorine silicone with excellent chemical resistance, solvent resistance and oil resistance, the expansion rate of the silica gel in nonpolar solvent small, cold resistance and good thermal stability, resistance to ignitability, therefore in the aircraft, rockets, missiles, space flight, in the petroleum chemical industry is used as the contact with the fuel oil and lubricating oil hose, gaskets, seals, fuel tank in the village, etc., Can also be used to manufacture corrosion resistant clothing, gloves, paint, adhesives, etc.
5. Because the polymer molecular side chain contains β -nitrile ethyl or γ -nitrile propyl strong polar groups, the intermolecular chain force is greatly increased, and the resistance to oil and solvent is improved. Meanwhile, due to the introduction of a certain amount of nitrile alkyl, the structure of the polymer is damaged, and the cold resistance is greatly improved. The type and content of nitrile alkyl, has a great impact on the performance, such as silica gel containing 7.5 grams of molecular % γ -propyl, low temperature performance and low phenyl silica gel (its glass temperature of -114.5℃), oil resistance than phenyl silica gel. With the increase of γ -nitrile propyl content to 33 ~ 50 mol %, the cold resistance decreased and the oil resistance improved. β -nitrile ethyl instead of γ -nitrile propyl can improve the heat resistance of nitrile silica gel, can withstand 250℃ hot air aging. The main advantage of nitrile silica gel is the excellent performance of oil resistance and bath resistance agent, can be kept elastic in the range of -60 ~ 180℃, therefore, can be made of oil resistant rubber products used in the aviation industry, automobile industry and petroleum industry; It can also be used as an environmental sealant for high performance aircraft and an oil tank sealant, and can maintain a seal from -54℃ to over 200℃. Nitrile silica gel can be processed by common equipment.