Nitrile is the most widely used elastomer in the seal industry. The popularity of nitrile is due to its excellent resistance to petroleum products and its ability to be compounded for service over a temperature range of -22°F to 212°F.

Nitrile is a copolymer of butadiene and acrylonitrile. Variation in proportions of these polymers is possible to accommodate specific requirements. An increase in acrylonitrile content increases resistance to heat plus petroleum base oils and fuels but decreases low temperature flexibility. Military AN and MS O ring specifications require nitrile compounds with low acrylonitrile content to insure low temperature performance.

Nitrile provides excellent compression set, tear, and abrasion resistance. The major limiting properties of nitrile are its poor ozone and weather resistance and moderate heat resistance, but in many applications these are not limiting factors.

Primary Uses

O-rings, rubber seals and custom moulded rubber components for:

Oil resistant applications

Low temperature applications

Fuel systems, automotive, marine, and aircraft

General Industrial Use

Application Advantages

excellent compression set,

superior tear resistance

abrasion resistance

Application Disadvantages

poor weather resistance

moderate heat resistance

Modifications

acrylonitrile content (ACN) from 18% to 50%

peroxide vs. sulphur donor cure system

XNBR improved wear resistance formulation

Specialized Applications

NBR NSF standard 61 for potable water applications

NBR WRc, KTW water applications

NBR FDA white list compounds