Nitrile rubber (NBR) O-ring
(A) Molecular structure
- (CH2-CH = CH-CH2) (CH2-CH) (CH2-CH),
CN of CH
‖
CH2
(B) physical and chemical properties
O-ring of nitrile rubber is a copolymer of acrylonitrile (ACN) and butadiene nitrile rubber O-ring performance mainly depends on which part of the CAN (usually 18% -50%), the CAN content higher than 50 % highly resistant to mineral oil and fuel capacity, flexibility at low temperature, compression rate deteriorates; butadiene higher formulations (78%), with good resistance to low temperature properties, but also the expense of the oil resistance at high temperatures. In short, the nitrile rubber O-ring has excellent oil resistance and resistance to non-polar solvent properties, but also have better mechanical properties and air tightness, suitable for aliphatic hydrocarbons (propane, hexane, mineral oil and grease, fuel oil), vegetable oil and animal oil, silicone oil, grease, chemical extinguishing agent, the acid-base salt solution diluted in the low temperature below 100 ℃, water and other media . However, anti-aromatic solvents, halogenated hydrocarbons, ketones, and lipid solvents and acid and alkali tolerance is poor. Nitrile rubber, weather resistance and ozone resistance capacity is not strong, but other materials and can be a good solution to this problem, such as: the NBR / PVC blends, not only has excellent weather resistance capacity and resistance to ozone, and flame-retardant, calendered, coloring ability is also very good, a certain amount of magnetic powder can be made into oil magnetic rubber, but its permanent compression deformation is poor.
(C) temperature range
A general level: -40 ~ 100 ℃
Resistance to low temperature level: -55 ~ 100 ° C
High temperature level; -30 ~ 125 ° C (air) -30 ~ 150 ° C (oil)
(D) hardness range
Shore A40 to 93 degrees
(5) Color
Black, brown, green, white, red, yellow, blue, orange, gray, and can be customer specified color
(F) Application
Nitrile rubber oil in a variety of occasions has been widely used. Automotive electronic injection fuel injector parts, all kinds of oil-resistant gaskets, seals, hoses. Hydraulic and pneumatic seals, cushion and other oil industry, wear rubber parts. In the nuclear industry, highly saturated nitrile rubber because of its resistance to radiation, can also be used for sealing of the nuclear installation.