Silicone rubber is widely used in electrical, electronic, office equipment, automotive, construction, medical, food and artificial organs and other fields because of its excellent weather resistance, high and low temperature resistance, electrical insulation, radiation resistance, biological inertia and so on. With the development of modern science and technology, the demand for heat resistance of silicone rubber in various fields is higher and higher. For example, the cabin temperature of aero-engine is often above 300 ℃, which puts forward higher requirements for oil resistance and high temperature resistance of rubber accessories.
The rare earth separation and application team of Baotou rare Earth Research Institute and Beijing Aeronautical Materials Research Institute of China have successfully developed a light rare earth heat resistant agent for silicone rubber and fluorosilicone rubber. The product has been tested and verified by Beijing Aeronautical Materials Research Institute of China, which can effectively improve the use temperature of silicone rubber and fluorosilicone rubber materials and improve their heat resistance grade. The heat resistance of silicone rubber products prepared with self-developed rare earth heat-resistant agents has reached the level of using similar imported products (Dow RMB-9001), which can realize the domestic substitution of this kind of high value-added heat-resistant agent products.
In the aerobic and high temperature environment, silicone rubber mainly occurs the degradation of main chain and the oxidation of side chain methyl, which leads to the decline of mechanical properties of silicone rubber. The addition of rare earth heat-resistant agent to silicone rubber can effectively improve the heat resistance of silicone rubber. The mechanism is that the redox rare earth elements can prevent the free radical reaction in silicone rubber due to oxidation in a certain temperature range. at the same time, rare earth metal compounds can absorb some trace acids or basic substances in silicone rubber that can catalyze the degradation reaction, thus play a role in thermal stability of silicone rubber.
Rare earth resources are valuable strategic resources, but the application field of light rare earth lanthanum and cerium resources is limited, the utilization rate of resources is low, the product backlog is large, and the market price is depressed for a long time, the core reason lies in the lack of development and application. The successful research and development of light rare earth heat-resistant agent for special rubber materials will help to promote the high-value utilization of lanthanum and cerium, which also shows that the combination of rare earth and polymer materials has a broad application prospect.
