Fluorosilicone rubber compound is a new material that combines the excellent properties of organic fluorine and organic silicon. It inherits the high and low temperature resistance and environmental aging resistance of organic silicon materials, as well as the oil resistance and chemical corrosion resistance of organic fluorine materials. These characteristics enable fluorosilicone rubber compound to maintain good physical and chemical properties under harsh environmental conditions.
Rubber aging refers to the changes in appearance such as softening, stickiness, hardening, cracking, mildew, color change, and the decline in mechanical properties such as tensile strength, elongation at break, and elasticity caused by the influence of external factors such as heat, oxygen, ozone, light, mold, and mechanical stress during processing, storage, or use. Although fluorosilicone rubber compound has high aging resistance, it may still age when exposed to harsh environmental conditions for a long time. This is mainly because the weak links such as unsaturated double bonds on the rubber molecular chain are easily attacked by external factors, resulting in molecular chain breakage or cross-linking, thereby causing performance changes.
Fluorosilicone rubber compound is particularly outstanding in terms of thermal aging. Due to its high dissociation energy of chemical bonds, fluorosilicone rubber compound has high thermal stability. At higher temperatures, fluorosilicone rubber compound is mainly degraded, but its degradation rate is relatively slow, thus ensuring its long-term stability in high temperature environments. In addition, the compression set performance of fluorosilicone rubber compound is also highly sensitive to thermal aging.
Ozone is much more chemically active than oxygen and is more destructive. The effect of ozone on rubber varies depending on whether the rubber is deformed or not. After ozone aging, an off-white hard and brittle film similar to spray frosting is formed on the surface of unstretched rubber. Under stress or strain, ozone cracking occurs in the film, and the crack direction is perpendicular to the force direction. Due to its high chemical bond dissociation energy, fluorosilicone rubber compound has relatively strong resistance to ozone, but it is still necessary to avoid long-term exposure to high ozone concentrations during use.
In particular, the ultraviolet part of sunlight, due to its short wavelength and high energy, can not only directly cause the breakage and cross-linking of rubber molecular chains, but also cause rubber to produce free radicals, triggering a free radical chain reaction. Although fluorosilicone rubber compound has relatively strong resistance to light, it may still experience light aging when exposed to strong sunlight for a long time. Therefore, during use, fluorosilicone rubber compound should be kept away from sunlight for a long time as much as possible.
In order to improve the aging performance of fluorosilicone rubber compound, a variety of measures can be taken. For example, by adding antioxidants, antiozonants, light stabilizers and other additives to enhance its resistance to heat, ozone and light; by optimizing the formula and processing technology to improve the overall performance of fluorosilicone rubber compound; and during use, pay attention to avoid long-term exposure to harsh environmental conditions.
For the evaluation and prediction of the aging performance of fluorosilicone rubber compound, a variety of methods can be used. For example, the hot air accelerated aging test method is used to evaluate the life of rubber materials based on the Arrhenius equation; the aging mechanism and performance change law of fluorosilicone rubber compound are studied through dynamic mechanical thermal analysis; and long-term performance monitoring and evaluation are carried out in combination with actual application environment and conditions. These methods can provide strong technical support and guarantee for the use and maintenance of fluorosilicone rubber compound.
Fluorosilicone rubber compound has excellent aging performance, but it is still necessary to avoid long-term exposure to harsh environmental conditions during use, and take necessary measures to improve its aging performance.
