Fluorosilicone rubber properties
Fluorosilicone rubber and methyl vinyl silicone rubber, compared with its oil resistance, solvent resistance, chemical resistance is extremely good; even compared with fluorine rubber, oil resistance, solvent resistance is also good.
1. Oil resistance, solvent resistance, chemical resistance
Fluorosilicone rubber and methyl vinyl silicone rubber, compared with its oil resistance, solvent resistance, chemical resistance is extremely good; even compared with fluorine rubber, oil resistance, solvent resistance is also good. In the same medium, temperature, time after impregnation have shown excellent durability, it can be said that fluorosilicone rubber is the only one in -68 ℃ ~ 232 ℃ under the resistance of non-polar media elastomer. Fluorosilicone rubber is also relatively good resistance to gasoline containing methanol, even in the gasoline / methanol mixed system, the hardness of the vulcanized rubber, tensile strength, volume changes are very small, after a long period of 500h impregnation test, the physical properties are almost unchanged.
2. Heat resistance
Fluorosilicone rubber decomposition at high temperatures with the same silicone rubber, namely: side chain oxidation, main chain fracture, thermal decomposition of the side chain and cause a variety of composite reactions. As the decomposition products will also cause the main chain fracture, so the heat resistance is usually worse than silicone rubber, at a temperature of 200 ℃ has begun to oxidize the aging. However, by adding iron, titanium, rare earth oxides and other small amounts of heat stabilizers can be made to obtain a significant improvement, even at a high temperature of 250 ℃ also has sufficient heat resistance. Temperature on the fluorosilicone rubber than silicone rubber, but smaller than the fluorine rubber. Foreign countries have also studied the fluorosilicone rubber at 150 ℃ × 2000h, 175 ℃ × 5000h, 200 ℃ × 4000h under the conditions of service life, the results are second only to methyl vinyl silicone rubber.
3. Cold resistance
Fluorosilicone rubber is as good as ordinary silicone rubber in low temperature performance. As fluorosilicone rubber is a soft Si-O main chain composed of linear polymers, so the low-temperature properties are better than the C-C main chain of fluorine rubber. Among them, fluorosilicone rubber (LS-2370U) has better low-temperature properties, with a brittleness temperature as low as -89℃, while general fluorine rubber is about -30℃.
4. Electrical properties, radiation resistance
Fluorosilicone rubber electrical properties and ordinary silicone rubber is similar, but especially valuable is in the high temperature, low temperature, humidity, oil, solvents, chemicals, ozone and other harsh conditions of the change is very small. Fluorosilicone rubber radiation resistance is not outstanding, but radiation aging resistance is better than methyl vinyl silicone rubber.
5. Physical and mechanical properties
Fluorosilicone rubber and ordinary silicone rubber, vulcanized rubber mechanical strength (especially tear strength) is relatively low. Therefore, to improve and enhance the strength of fluorosilicone rubber is also an important research topic.
6. Other properties
Fluorosilicone rubber weather aging resistance is very good, even after 5 years of exposure, still maintains good performance. Ozone is one of the gases generated by the elastomer aging the most, but fluorosilicone rubber through dynamic or static tests have not been found to have cracked or cracked phenomenon. In addition, the mold resistance, physiological inertness, and anticoagulant properties of fluorosilicone rubber are also very good.
Fluorosilicone preparation method or source
Synthesized with carbon tetrafluoride and ethylene as starting materials. It can be prepared by catalytic polymerization of trimethyltris(3-fluoropropyl)cyclotrisiloxane and a small amount of tetramethyltetravinylcyclotetrasiloxane (containing a small amount of capping agent) in the presence of a catalyst.