Nowadays, many fields tend to add rare earths to improve the comprehensive properties of materials. The application of rare earths in silicone rubber is a new field. Using the unique electronic layer structure of rare earths and the characteristics of easy formation of complexes, a variety of rare earth functional additives can be prepared. , not only can improve the mechanical properties of silicone rubber, improve its heat resistance and flame retardancy, but also have a significant effect in giving it new functions. The prepared silicone rubber composite material combines the advantages of silicone rubber and other materials, with Excellent thermal stability, safety and environmental protection, are widely used in national defense, transportation, medical and other fields.
So, what are the typical uses of rare earths in silicone rubber?

1. Improve flame retardancy
Silicone rubber is widely used in the power industry due to its excellent insulation and hydrophobicity. Flame retardants are usually added to silicone rubber to improve its flame retardant performance, but general halogenated flame retardants will generate a lot of toxic fumes when burning, causing serious pollution to the environment, so more and more green, Rare earth flame retardant that is non-toxic, environmentally friendly, and can maintain good mechanical properties of the material to improve the flame retardancy of silicone rubber. The addition of rare earth oxides not only reduces the amount of inorganic flame retardants, but also increases the carbon residue rate of the composites and significantly improves their thermal stability.

2. Improve heat resistance
The transition metal compound can interact with the network structure of the silicone rubber, thereby improving its thermal stability. The addition of transition metal compounds and rare earth oxides, such as Fe2O3 and titanium dioxide (TiO2), can effectively improve the heat resistance of silicone rubber; the addition of cerium oxide can significantly improve the degree of re-crosslinking during aging, reduce the number of pores on the friction surface, and make silicon Rubber has better mechanical properties, friction properties, and thermal-oxidative aging resistance. Nano cerium oxide, as a heat-resistant additive, plays an important role in the preparation of light-colored silicone rubber.

3. Improve the fluorescence
The fluorescence generated by the coordination of rare earth ions with organic ligands combines the advantages of high luminescence intensity of rare earth ions and low excitation energy of organic compounds. Therefore, adding rare earth compounds into silicone rubber can make it have special fluorescence properties, and it has a wide range of application prospects.

Fourth, enhance the mechanical properties
Affected by various factors during processing or use, silicone rubber will appear discolored, hardened, and brittle, which hinders many of its potential applications. An effective way to improve the mechanical strength of silicone rubber is to add inorganic fillers, such as carbon black, silica, etc. Among them, white carbon black is easy to be modified due to its large specific surface area and a large number of silyl hydroxyl groups on the surface, and is widely used in silicone rubber reinforcement. Rare earth modifiers also have a good reinforcing effect on silicone rubber. For example, when 0.02% of nano-cerium oxide is added, the mechanical properties of the composite material are significantly improved, and the light transmittance can reach more than 85%, which greatly improves The encapsulation advantages of silicone rubber used to encapsulate light-emitting diodes.

5. Enhance radiation resistance
Traditional radiation-resistant silicone rubber composites contain substances such as lead or phenyl, which are costly, have limited radiation resistance, and pollute the environment. Rare earth compounds, as radiation-resistant additives for silicone rubber, have the advantages of green, environmental protection and high efficiency. For example, yttrium oxide, cerium oxide, gadolinium oxide, etc., whether the rare earth oxide is used alone, or the rare earth oxide is blended, or the rare earth oxide is used in combination with traditional radiation resistance additives, the radiation resistance of the material can be improved. photogenic.