Nitrile Butadiene Rubber (NBR), nitrile rubber for short, is an elastomer.
NBR is resistant to oils, fats, hydrocarbons and dilute acids and has good mechanical properties. It is limited weather and ozone resistant. It is not resistant to aromatic compounds, halogenated hydrocarbons, ketones, automotive brake fluid or strong acids. The operating temperature is limited to approx. 110°C.
The properties of nitrile rubber are partly determined by the acrylonitrile content, which can vary from 18 to about 50%. Standard NBR contains approximately 34% acrylonitrile. More acrylonitrile improves mechanical properties and resistance to oil and fuel, but increases the temperature at which the rubber becomes brittle.
Seals, pipes, medical gloves, belts, cable coverings and the like are manufactured from NBR; it is the most commonly used elastomer for seals such as O-rings. Rubber bellows mechanical seals can also be made of NBR.