Abstract: In order to study the effect of short carbon fiber on the mechanical and tribological properties of nitrile rubber, different mass fractions of short carbon fiber (CF) were added to nitrile rubber (NBR) by mechanical blending to carry out tensile and tear tests. Combined with the three-dimensional morphology and scanning electron microscopy, the friction properties of 0 and 15 parts of short CF vulcanizate under different loading force and speed were analyzed. The results show that short CF can enhance the matrix strength of nitrile rubber and increase its hardness. However, when the addition is excessive, the degree of bonding of the short CF to the rubber matrix is decreased, and the fiber is easily pulled out during stretching, tearing and rubbing. Adding 15 parts of short CF to the nitrile rubber reduces the friction coefficient and the amount of wear. The CF/NBR friction coefficient is less affected by the rotating speed. When the rotating speed is higher, the frictional interface of the vulcanized rubber will generate a large amount of thermal energy, which will cause melting phenomenon, resulting in less grinding debris. During the friction process, the short CF and the rubber matrix jointly carry the force, so that the CF/NBR composite has good wear resistance.

Key words: nitrile rubber, short carbon fiber, mechanical properties, friction properties