FVMQ fluorosilicone O-ring maintains the excellent properties of organic silicone materials such as heat resistance, cold resistance, high voltage resistance, and weather aging resistance. Due to the introduction of fluorine-containing groups, it also has the excellent properties of organic fluorine materials. Resistant to hydrogen solvents, oil, acid and alkali and lower surface energy properties[1]
Also known as γ-trifluoropropylmethylpolysiloxane. Generally, 0.2% to 0.4% vinyl siloxane copolymerization modification is introduced into the molecular chain. It is a colorless, transparent and highly viscous plastic linear polymer compound. The main chain is composed of silicon and oxygen atoms. The side groups connected to silicon are methyl, vinyl and trifluoropropyl groups. The molecular weight is between 500,000 and 800,000. With various additives, it can be mixed into a homogeneous rubber material. Under the action of organic peroxide, it can be vulcanized into various elastic rubber products. In addition to the properties of general silicone rubber, it also has excellent resistance to aviation fuel oil, hydraulic oil, engine oil, chemical reagents and solvents. It can work for a long time at -55~+200℃.
Fluorosilicone rubber uses:
Fluorosilicone rubber is a type of special synthetic rubber. It combines the high temperature resistance of silicone rubber with the corrosion resistance and oil resistance of fluorine rubber. Suitable for aircraft fuel tank sealing materials, engine accessories, fuel oil hoses, hydraulic system sealing rings, pump diaphragms, etc., as well as various high and low temperature resistant, oil resistant, chemical resistant diaphragms, fluorosilicone rubber gaskets, and fluorosilicone rubber O-rings, pipes, seals, etc.
Properties of fluorosilicone rubber:
Fluorosilicone rubber is a type of silicone rubber with fluoroalkyl groups introduced into the side chain. Commonly used fluorosilicone rubber is fluorosilicone rubber containing methyl, trifluoropropyl and vinyl.
Fluorosilicone has good heat resistance and excellent oil resistance and solvent resistance, such as aliphatic hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons, various petroleum-based fuel oils, lubricating oils, hydraulic oils and some synthetic oils at room temperature. The stability under high temperature is good, which is beyond the reach of simple silicone rubber. Fluorosilicone rubber has good low-temperature properties, which is a great improvement over pure fluorosilicone rubber. The temperature range for fluorosilicone rubber containing trifluoropropyl to maintain elasticity is generally -50°C to +200°C. Its high and low temperature resistance is worse than that of vinyl silicone rubber, and it will produce toxic gases when heated to above 300°C. It is much worse than vinyl silicone rubber in terms of electrical insulation properties. Adding an appropriate amount of low-viscosity hydroxyfluorosilicone oil to the fluorosilicone rubber compound, heat-treating the compound, and adding a small amount of vinyl silicone rubber can significantly improve the process performance and help solve problems such as the rubber compound sticking to the roller and serious storage structure. , can extend the effective life of the rubber. When the methylphenylsilicone chain link is introduced into the above-mentioned fluorosilicone rubber, it will help to improve the low temperature resistance and have good processing performance.
The main advantages of fluorosilicone rubber are as follows:
1. Oil, solvent and chemical resistance
Compared with methyl vinyl silicone rubber, fluorosilicone rubber has extremely excellent oil resistance, solvent resistance, and chemical resistance; even compared with fluororubber, its oil resistance and solvent resistance are also good. It shows excellent durability after immersion in the same medium, temperature and time. It can be said that fluorosilicone rubber is the only elastomer that can withstand non-polar media at -68°C ~ 232°C. Fluorosilicone rubber also has relatively good resistance to methanol-containing gasoline. Even in a gasoline/methanol mixed system, the hardness, tensile strength, and volume changes of its vulcanized rubber are very small. After a long 500-hour immersion test, various physical properties Very little has changed either.
2.Heat resistance
The high temperature decomposition of fluorosilicone rubber is the same as that of silicone rubber, namely: side chain oxidation, main chain breakage, side chain thermal decomposition and various composite reactions. Since the decomposition products can also cause the main chain to break, the heat resistance is usually worse than that of silicone rubber, and it has begun to oxidize and age at a temperature of 200°C. However, by adding a small amount of heat stabilizers such as iron, titanium, rare earth oxides, etc., it can be significantly improved, and it has sufficient heat resistance even at a high temperature of 250°C. The effect of temperature on fluorosilicone rubber is greater than that of silicone rubber, but less than that of fluororubber. Foreign studies have also studied the service life of fluorosilicone rubber under the conditions of 150℃×2000h, 175℃×5000h, and 200℃×4000h. The results are second only to methyl vinyl silicone rubber.
3. Cold resistance
Fluorosilicone rubber, like ordinary silicone rubber, has good low-temperature properties. Since fluorosilicone rubber is a linear polymer composed of soft Si-O as the main chain, its low temperature characteristics are better than those of fluororubber with C-C as the main chain. Among them, fluorosilicone rubber (LS-2370U) has better low-temperature characteristics, with a brittleness temperature as low as -89°C, while ordinary fluorosilicone rubber is about -30°C.
4. Electrical properties and radiation resistance
The electrical properties of fluorosilicone rubber are similar to ordinary silicone rubber, but what is particularly valuable is that it changes very little under harsh conditions such as high temperature, low temperature, moisture, oil, solvents, chemicals, and ozone. The radiation resistance of fluorosilicone rubber is not outstanding, but its radiation aging resistance is better than that of methyl vinyl silicone rubber.
5.Physical and mechanical properties
Fluorosilicone rubber is the same as ordinary silicone rubber. The mechanical strength of vulcanized rubber (especially tear strength) is relatively low. Therefore, improving and increasing the strength of fluorosilicone rubber is also an important research topic.
6.Other features
Fluorosilicone rubber has excellent weather aging resistance and still maintains good performance even after 5 years of exposure. Ozone is one of the most generated gases when elastomers age, but no cracks or cracks have been found in fluorosilicone rubber after dynamic or static tests.
Fluorosilicone rubber
