Silicone rubber is a polymer elastic material with both molecular and inorganic properties. Its molecular chain consists of alternating silicon and oxygen atoms (-SI-O-SI-). The silicon-oxygen bond energy is much larger than that of ordinary rubber. This is a very high heat of silicone rubber. One of the main reasons for stability. Its molecular side chain is a hydrocarbon or a substituted hydrocarbon organic group attached to a silicon atom. In the early stage, this group was a methyl group. Later, in order to improve the vulcanization activity and other modification of the raw rubber, it gradually developed. A very small amount of unsaturated vinyl groups (generally no more than 0.5 MOL%) or other organic substituent groups are introduced into the side chains. This low-unsaturation molecular structure gives silicone rubber excellent heat aging and weathering resistance, and is very stable to ultraviolet light and ozone.
1. Excellent high and low temperature resistance
Silicone rubber has the widest operating temperature range (-100 ~ 350 °C), but it must be pointed out that silicone rubber has high temperature and temperature tightness and poor aging performance, that is, when insulating air, especially when water is present, it will cause silicone rubber. The mechanical strength drops rapidly and even cracks into low molecular weight. This disadvantage can be achieved by adding a special heat-resistant stabilizer, a compound of hydrazine.
2, excellent resistance to ozone aging, oxygen aging, weathering resistance
After the silicone rubber vulcanizate was placed in the free state for several years, the performance did not change significantly.
3, excellent electrical insulation properties
The silica formed after combustion is still an insulator, and its corona resistance and arc resistance are extremely good.
4, special surface properties and physiological inertia
The surface energy of silicone rubber is lower than that of most organic materials. Therefore, it has low hygroscopicity. Its long-term immersion in water has a water absorption rate of only 1%, physical and mechanical properties are not lowered, and mildew resistance is good. Moreover, it is not sticky to materials. Can be used for isolation. Silicone rubber is odorless, non-toxic and has no adverse effects on the human body.
5, high permeability
The penetration of N2, O2 and air at room temperature is 30 to 40 times higher than that of NR. It also has the property of selecting gas permeation, and the permeability to O2 is 1 times that of N2.
6. The special silicone rubber is resistant to oil, radiation and fire.
A. Oil resistance: For aliphatic, aromatic and chlorinated hydrocarbon solvents, petroleum-based fuel oils, lubricating oils, hydraulic oils, etc. are very stable at normal temperature and high temperature, and have good properties for ethanol, acetone, etc. Resistance.
B, flame retardancy
It can be made using a flame retardant.
C, radiation resistance
Vulcanized silicone rubber
Silicone rubber with a molecular weight of 40-600,000, using peroxide as the basic property of vulcanizing agent silicone rubber
Properties: Silicone rubber is composed of silicon and oxygen atoms, and the side chain is a carbon-containing group. The largest amount is silicone rubber with a side chain of vinyl. It is heat-resistant and cold-resistant. It has a temperature range of -100 to 300 ° C. It has excellent weather resistance and ozone resistance as well as good insulation. The disadvantages are low strength, poor tear resistance and poor wear resistance. Uses: high temperature insulation seal, medical materials, high voltage cable, adhesive, precision mold, insulation. Silicone rubber is mainly used in the aviation industry, electrical industry, food industry and medical industry. Introduction to Silicone Rubber Silicone rubber is a linear polymer elastomer containing silicon-oxygen bonds (Si-O) and thus has high thermal stability. It has excellent resistance to ozone aging, oxygen aging, photoaging and weathering. It also has excellent electrical insulation properties, mildew resistance and high gas permeability. It can make many model products, such as various O-rings and gaskets. , cups, oil seals, valves, shock absorbers and diaphragms. Because silicone rubber is physiologically inert, non-toxic, non-adhesive with other materials, and can withstand multiple cooking and disinfection features, it is widely used in the medical and food industries, such as artificial heart valves, artificial throats, artificial blood vessels, pacifiers and Medicine bottle stoppers, etc. As a coating and sealing of various electronic tubes or electrical components, it has the effects of moisture-proof, dust-proof, shock-proof and improved electrical properties.
The role of silicone rubber in the wire and cable industry
Because silicone rubber has good electrical insulation properties, high temperature resistance, oil resistance, radiation resistance and fire resistance. For the wire and cable industry, it is also widely used, such as: silicone rubber wire, high temperature resistant silicone wire, flame retardant silicone wire, oil resistant silicone wire, flame resistant silicone wire and other products are developed through the special advantages of silicone rubber. It can be widely used in various industries.