Fluorosilicone rubber is a silicone elastomer with side chain modification. Common products made of fluorosilicone rubber not only have the characteristics of general silicone rubber, but also have excellent oil resistance, including fuel, engine oil, chemical reagents and solvents. Therefore, fluorosilicone rubber makes up for the lack of oil resistance of ordinary silicone rubber, and can be called the "oil fighter" in silicone elastomers.
Compared with methyl vinyl silicone rubber, fluorosilicone rubber has excellent oil resistance, solvent resistance, and chemical resistance. Even compared with fluoro rubber, it has good oil and solvent resistance. After being immersed in the same medium, temperature and time, it shows excellent durability. It can be said that fluorosilicone rubber is the only elastomer that is resistant to non-polar media at -68°C to 232°C.
Fluorosilicone rubber has better resistance to methanol-containing gasoline. Even in a gasoline/methanol (85vol% / 15vol%) mixed system, the hardness, tensile strength and volume change of the vulcanized rubber are very small. After a long time of 500h After the immersion test, the physical properties hardly changed.
Heat resistance
The high-temperature decomposition of fluorosilicone rubber is the same as that of silicone rubber, that is, side chain oxidation, main chain fracture, side chain thermal decomposition and cause a variety of complex reactions.Because the decomposition products also cause the main chain to break, the heat resistance is usually a little worse than that of silicone rubber, which has begun to oxidize and age at 200℃.However, by adding a small amount of heat stabilizer such as iron, titanium and rare earth oxide, it can be significantly improved and has sufficient heat resistance even at 250℃.
The influence of temperature on fluosilicate rubber is greater than that of silicone rubber, but less than that of fluorosilicate rubber.The service life of fluorosilicone rubber at 150℃×2000h, 175℃×5000h and 200℃×4000h were also studied abroad, and the result was second only to methylvinyl silicone rubber.
Cold tolerance
Fluorosilicone rubber and ordinary silicone rubber, low temperature performance is good.Because fluorosilicone is a linear high polymer with soft Si-O main chain, its low temperature property is better than that of Fluorosilicone with C-C main chain.Among them, the low temperature characteristic of fluorosilicone rubber (LS-2370U) is better, and the brittle temperature is as low as -89℃, while the general fluorosilicone rubber is about -30℃.
Electrical and radiation resistance
The electrical properties of fluorosilicone rubber are similar to those of ordinary silicone rubber, but the special value is that the changes in high temperature, low temperature, humidity, oil, solvent, chemicals, ozone and other harsh conditions are very small.
The radiation resistance of fluorosilicone rubber is not outstanding, but the radiation resistance of fluorosilicone rubber is better than that of methyl vinyl silicone rubber.
Physico-mechanical properties
Like common silicone rubber, the mechanical strength of vulcanized rubber (especially tear strength) is relatively low.Therefore, to improve and improve the strength of fluorosilicone rubber is also an important research topic.
Weather resistance
Fluorosilicone rubber is very resistant to weathering and retains good performance even after 5 years of exposure.Ozone is one of the gases generated most when the elastomer is aging, but no cracking or cracking has been found after the dynamic or static tests of fluorosilicone rubber.
The application of fluorine silicone
Because of its excellent performance, fluorine silica gel has been used in many fields.
1. Automobile industry: all kinds of vehicles, turbocharged pipe, extrusion strip, sealing ring, oil seal, diaphragm, conduit, valve lining, etc.
2. Petrochemical industry: all kinds of high temperature, low temperature, chemical resistance to the erosion of pumps, valves, oil tanks and other equipment sealing products.
3. Aviation industry: seals and contacts that are resistant to fuel oil and lubricating oil on aircraft, such as various O-rings, fillers, sealing rings, sensor materials, diaphragms and gaskets.
4. Medical care: used for medical devices and artificial organs, such as medicinal catheter, drainage tube, artificial valve, etc.
5. Military industry: low temperature/oil/acid resistant harsh environments, e.g., fluid bellows for hydraulic systems of military aircraft, doors and Windows/rear cover seals for special vehicles, sensing materials for sensors.
