Fluorosilicone rubber is a type of silicone rubber with […]
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 and solvent resistance, such as aliphatic hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons, petroleum-based various fuel oils, lubricating oils, hydraulic oils and some synthetic oils at room temperature The stability at high temperature is better, which is not as good as pure silicone rubber. Fluorosilicone rubber has good low temperature performance, which is a great improvement for pure fluororubber. The temperature range of fluorosilicone rubber containing trifluoropropyl group to maintain elasticity is generally -50℃~+200℃, and its resistance to high and low temperature is worse than that of vinyl silicone rubber, and it will generate toxic gas when heated above 300℃. In terms of electrical insulation properties, it is much worse than vinyl silicone rubber. Adding an appropriate amount of low-viscosity hydroxyfluorosilicone oil to the fluorosilicone rubber compound, heat treatment of the compound, and adding a small amount of vinyl silicone rubber can significantly improve the process performance and help solve the problems of rubber sticking to rollers and serious storage structure. , Can extend the effective life of the rubber compound. When the methyl phenyl silicone chain link is introduced into the above-mentioned fluorosilicone rubber, it will help to improve the low temperature resistance, and the processing performance is good.
Nitrile silicone rubber is a type of silicone rubber with nitrile alkyl groups (usually β-nitrile ethyl or γ-nitrile propyl) introduced into the side chain. The introduction of polar nitrile groups improves the oil resistance and durable solvent performance of silicone rubber, but its heat resistance, electrical insulation and processability are reduced.
The type and content of nitrile alkyl groups have a greater impact on the performance of nitrile silicone rubber. For example, silicone rubber containing 7.5% moles of γ-nitrile propyl group has similar cold resistance to low phenyl silicone rubber and lower oil resistance. The base silicone rubber is better. When the content of γ-cyanopropyl group increases to 33~50% moles, the cold resistance is significantly reduced, the oil resistance is improved, and the heat resistance is 200°C. If β-nitrile ethyl is used instead of γ-nitrile propyl, the heat resistance of nitrile silicone rubber can be further improved.