NBR:
Composing:
To the chemist this rubber is known as Acrylonitrile butadiene rubber, to others it is called Buna-N but to many people in the industry, simply, nitrile. It is the workhorse of the marketplace for its oil resistant properties. The grades offered differ in the percentage of acrylonitrile (ACN) in the polymer chain as well as the overall viscosity of the polymer.

Properties and Applications:
The higher the amount of ACN in the elastomer the better the oil resistance; the lower end of the ACN distribution range being approximately equivalent to the oil resistance of CR and therefore only having a moderate level of oil resistance. NBR also has superior fuel resistance. The terms oil and fuel used here refers loosely to those products derived from petroleum.The weather resistance of NBR is poor, similar to NR and SBR, although it can be enhanced by blending with the plastic, polyvinyl chloride (PVC), at some 'cost' to its low temperature properties. The lower the percentage of ACN in the polymer, the better the low temperature flexibility, and the poorer the oil resistance. Special compounding ingredients can be added to increase heat aging resistance. Like SBR, NBR needs reinforcing fillers to give good mechanical properties.NBR is a distinctly polar rubber, hence its excellent resistance to non polar petroleum oils. This also that NBR has poor resistance to polar liquids such as ketones, esters, chlorinated solvents, and highly aromatic solvents such as benzene and toluene.