Nitrile rubber

Nitrile rubber is a synthetic rubber. The short name is derived from NBR Nitrile Butadiene Rubber (Nitrile Butadiene Rubber ). Nitrile rubber is obtained by copolymerization of acrylonitrile (ACN) and 1,3-butadiene obtained. The material also has the brand name Buna -N ® and Buna N ®.

The vulcanizates prepared from nitrile rubber have high resistance to oils, greases and hydrocarbons, good aging behavior and low abrasion. They are used for the production of gaskets, hoses, rubber gloves, and the rubber threads.

The acrylonitrile content in NBR may lie between 18 and 50 percent, and affects the following properties:

  • Resistance to swelling in mineral oils, greases and fuels
  • Elasticity
  • Temperature flexibility
  • Gas permeability
  • Compression set

So shows a NBR material with 18 percent ACN content a very good low-temperature flexibility down to about -38 ° C at moderate oil and fuel resistance, one having 50 percent ACN content, however, a low-temperature flexibility only to about - 3 ° C, but optimum oil and fuel resistance. With increasing ACN content to reduce the elasticity and permeability to gas, the compression set deteriorates.

Materials based on this synthetic rubber are suitable because of their good technological properties for many applications. In particular, radial shaft seals, sealing elements for hydraulic and pneumatic systems as well as O -rings are manufactured in large quantities of materials on NBR basis.

  • Good resistance to swelling in aliphatic hydrocarbons, such as propane, butane, gasoline, mineral oils ( lubricating oils, hydraulic oils of groups H, HL and H- LP) and mineral oil based grease, fire-resistant hydraulic fluids of the groups HFA, HFB and HFC, vegetable and animal oils and fats, light fuel oil, diesel fuel. Some materials are particularly resistant to hot water temperatures up to 100 ° C ( sanitary fittings) as well as inorganic acids and bases is not too high concentration and temperature.
  • Medium resistance to swelling in fuels with high aromatic content ( premium fuel ).
  • Strong swell in aromatic hydrocarbons, such as benzene, chlorinated hydrocarbons, such as trichlorethylene, fire-resistant hydraulic fluids of the group HFD, esters, polar solvents, brake fluids, glycol ether.
  • Operating temperature range: Depending on the composition of compound between -30 ° C and 100 ° C, briefly up to 130 ° C; at higher temperatures the material hardens.

The cold enough flexibility for special mixtures to -55 ° C.

See also: HNBR, styrene-butadiene rubber (SBR), natural rubber

  • Copolymer
  • Elastomer
Vulcanization Hydraulics Base (chemistry) Glycol ethers
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