Nitrile Butadiene Rubber

Product

Nitrile (often referred to as buna-N rubber or perbunan) is the most commonly used elastomer in the seal industry. Nitrile is a copolymer of two monomers: acrylonitrile (ACN) and butadiene. The properties of these rubber compounds are determined by its ACN content, which is broken down into three classifications:

The higher the ACN content, the better its resistance to hydrocarbon oils. The lower the ACN content the better its flexibility in low temperature applications. Medium nitrile is, therefore, most widely specified due to its good overall balance in most applications. Typically, nitriles can be compounded to work over a temperature range of –35°C to +120°C and are superior to most elastomers in regard to compression set, tear and abrasion resistance.

How it’s produced

Nitrile is produced by emulsifying butadiene and acrylonitrile together in water, then polymerizing the result, which converts the single unit molecules of the new combined material into larger molecules with multiple units. The end product can have from 15% to 50% acrylonitrile content, depending on the characteristics the manufacturer wants the rubber to have.

Applications

Automotive Industry

Gaskets
Seals
O-rings
Carburetor and fuel pump diaphragms
Fuel systems
Hydraulic hoses
Tubing

Bowling Industry

Oil & Gas Industry

Seals
Tubing
Molded shapes
Rubber-to-metal bonded components
Connectors
(BOP) Blowout preventers
Stripper rubber
Rotating heads

Properties

Nitrile Rubber belongs to the family of unsaturated copolymers of acrylonitrile and butadiene.
The physical and chemical properties of nitrile rubber vary depending on the polymer’s composition of acrylonitrile.
Different grades are available for this rubber. The higher the acrylonitrile content within the polymer, the higher the oil resistance.
It can withstand a range of temperatures.
It has inferior strength and flexibility, compared to natural rubber.
Nitrile rubber is also resistant to aliphatic hydrocarbons.
It is less resistant to ozone, aromatic hydrocarbons, ketones, esters and aldehydes.
It has high resilience and high wear resistance but only moderate strength.
It has limited weathering resistance.
It can generally be used down to about -30 degree celcius , but special grades can also operate at lower temperatures.