Silicone O-ring properties Description: Silicone (Silica gel; Silica) Alias: Silicone rubber is a highly active adsorption material is amorphous material, its chemical formula is mSiO2 · nH2O. Insoluble in water and any solvent, non-toxic, odorless, chemically stable, does not react with any substance except alkali, hydrofluoric acid. Various types of silica because of the way they are formed of different porous structures. Chemical composition and physical structure of the silica gel, determines that it has many other similar material was difficult to replace characteristics: high adsorption properties, good thermal stability, chemical stability, high mechanical strength. Silicone divided according to their pore size: large pore silica, coarse pore silica gel, B-type silica gel, silica pores. Silicone rubber molecular structure: CH3 CH = CH - (Si-O) (Si-O) methyl vinyl silicone rubber O-ring CH3 CH3 physical and chemical properties of silicone rubber: silicone material is silicon elements obtained from quartz-based, and is formed by adhering the silicon atoms such as methyl, vinyl and other non-polar side chain saturated rubbers. Will lead to different side chains of silicone rubber having different characteristics. Methyl vinyl silicone rubber (VMQ) is the application of more of a silicone rubber O-ring silicone O-ring material. Food grade silicone o-ring excellent in heat resistance, particularly excellent elasticity and resistance to oxidation and ozone low temperature, has a high permeability and selectivity of gas permeable. Good electrical insulating properties (volume resistivity greater than 1016 European .cm, breakdown voltage 30kv / mm or more), corona resistance and arc resistance. But adding conductive carbon black, nickel powder, aluminum powder, silver powder, but also to give the appropriate conductivity (volume resistivity up to 5-0.02 Europe .cm). Silicone rubber is hygroscopic, can play a role in isolation. Water, but poor resistance to water vapor pressure over 50psi above is not recommended. And a solvent compatible with most of the oil, chemicals. General silicone rubber acid resistance, resistance to polar solvents is acceptable, intolerance hydrogen and alkyl aromatic oils. Caustic soda solution is not recommended for use in most concentrated solvents, oils, concentrated acid and diluted in. Special silicone rubber is also resistant to radiation, fire, oil and other properties. Its low tensile strength, abrasion resistance is weak, generally not used for dynamic sealing.