NBR is a copolymer of butadiene and acrylonitrile, and the content of bound acrylonitrile has a great influence on its mechanical properties, adhesive properties and heat-resistant properties. Due to the role of the polarity factor of acrylonitrile, increasing the content of acrylonitrile can improve the adhesive strength of NBR. Therefore, it is very important to test the bonding acrylonitrile content in NBR.

Acrylonitrile content has a great influence on the performance of NBR. The acrylonitrile content of general-purpose acrylonitrile NBR is between 15%~50%, if the acrylonitrile content is increased to more than 60%, it will be hardened, similar to leather, and no longer has rubber properties.

1, Oil resistance and solvent resistance: NBR has oil resistance in ordinary rubber. NBR is more resistant to petroleum-based oils, benzene and other non-polar solvents than natural rubber, styrene butadiene rubber, butyl rubber and other non-polar rubbers, but also better than polar chlorinated rubber.

2、Physical Property Characteristics: Nitrile rubber is a nitrile copolymer with random structure, which will not crystallise under stretching. Therefore, the physical and mechanical properties of pure NBR vulcanised rubber are the same as styrene NBR, which is much lower than natural rubber. Nitrile vulcanised rubber reinforced (i.e. adding reinforcing fillers, such as carbon black and phenolic resin), the tensile strength can reach the level of natural rubber, usually around 24.50mpa, with the increase of the polar content of this NBR, the flexibility of the macromolecular chain decreases, increasing the intermolecular atomic force, the double bond decreases, and the macromolecular chain is not saturated, thus bringing a series of changes in the performance of the Nitrile Rubber, NBR is very suitable for the manufacture of Shock absorbers with high oil resistance. The elasticity of NBR with the combination of acrylonitrile and the characteristics of change

3, air permeability: NBR has better air tightness than natural rubber and styrene butadiene rubber, but not as good as polysulphur rubber, which is about the same as butyl rubber.

4、Low temperature performance: NBR has poor low temperature performance in general rubber. Low temperature performance and acrylonitrile content, glass transition temperature increases with the increase of acrylonitrile content.

5、Heat resistance: the heat resistance of NBR is better than that of natural rubber and styrene butadiene rubber. Choosing suitable formula, NBR products can be used continuously at 120℃; it can withstand hot oil at 150℃; immersed in oil at 191℃ for 70 hours, it still has the ability to flex.

6. Ozone resistance: the ozone resistance of NBR is not good, generally add ozone-resistant agent to improve it, but in use with oil contact with the product is easy to take out the ozone-resistant agent and lose the ozone-resistant effect. Combined with PVC, the effect is remarkable.

7、Water resistance: NBR has better water resistance. The higher the content of acrylonitrile, the better the water resistance.

8、Electrical insulation performance: NBR has poor electrical insulation performance due to its polarity. It belongs to semiconductor rubber and should not be used as insulating material.

9, aging resistance: the aging resistance of NBR without antioxidant is very poor, while the aging resistance and heat resistance of NBR with antioxidant is better than that of natural rubber. After thermo-oxidative aging, the tensile strength of natural rubber is greatly reduced, but the reduction of NBR is actually very small.

10, radiation resistance:
NBR may also be damaged under nuclear radiation, resulting in increased hardness and reduced elongation. However, compared with other synthetic rubbers, NBR is less affected by radiation, and NBR with an acrylonitrile content of 33%-38% has good radiation resistance.