What Are The Important Characteristics Of Fluorosilicone Rubber
1. Oil resistance, solvent resistance, chemical resistance
Compared with methyl vinyl silicone rubber, fluorosilicone rubber has excellent oil resistance, solvent resistance, and chemical resistance; even compared with fluororubber, oil resistance and solvent resistance are also good. After dipping in the same medium, temperature and time, they all show 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. The resistance of fluorosilicone rubber to gasoline containing methanol is also relatively good. Even in the gasoline/methanol mixed system, the hardness, tensile strength and volume change of the vulcanized rubber are very small. After 500h long-term immersion test, the physical properties There was also little change.
2. Heat resistance
The pyrolysis of fluorosilicone rubber is the same as that of silicone rubber, namely: side chain oxidation, main chain breakage, side chain thermal decomposition and various compound 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, it can be significantly improved by adding a small amount of heat stabilizers such as iron, titanium, and rare earth oxides, and it has sufficient heat resistance even at a high temperature of 250°C. The influence of temperature on fluorosilicone rubber is greater than that of silicone rubber, but smaller than that of fluororubber. Foreign countries have also studied the service life of fluorosilicone rubber under the conditions of 150°C×2000h, 175°C×5000h, and 200°C×4000h, and the result is second only to methyl vinyl silicone rubber.
3. Cold resistance
Like ordinary silicone rubber, fluorosilicone rubber has good low temperature performance. Since fluorosilicone rubber is a linear polymer composed of soft Si-O as the main chain, its low temperature properties are better than those of fluororubber with C-C as the main chain. Among them, fluorosilicone rubber (LS-2370U) has better low temperature properties, and the brittle temperature is as low as -89°C, while the general fluororubber is about -30°C.
4. Electrical properties, radiation resistance
The electrical performance of fluorosilicone rubber is similar to that of ordinary silicone rubber, but it is particularly valuable in that it changes little under harsh conditions such as high temperature, low temperature, humidity, oil, solvent, 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
Like ordinary silicone rubber, fluorosilicone rubber has relatively low mechanical strength (especially tear strength) of vulcanized rubber. Therefore, improving and increasing the strength of fluorosilicone rubber is also an important research topic.
6. Other features
The weather resistance of fluorosilicone rubber is very good, even after 5 years of exposure, it still maintains good performance. Ozone is one of the most generated gases during the aging of elastomers, but no cracks or cracks have been found in fluorosilicone rubber through dynamic or static tests. In addition, the mildew resistance, physiological inertia and anticoagulant properties of fluorosilicone rubber are also very good.
