The wear resistance of natural rubber-trans-polyisoprene rubber composites under high loads and high speeds

Aircraft tires are used at high speeds and loads, and the wear resistance of tread rubber composites directly affects the service life of tires. Using a homemade rubber abrasion device to simulate the high speed (> 11 Hz) and high load (> 1.8 MPa) on the tire during the actual driving process, the effects of load, rotation speed and carbon black (CB) loading on the wear resistance of natural rubber-trans-polyisoprene (NR-TPI) composites were investigated, and the related influencing mechanisms were proposed by combining the morphology of rubber surface and the morphological characteristics of wear debris. The results show that the abrasion of rubber increases with the increase of load. The effect of rotation speed on the abrasion rate is less than that of load. When the rotation speed increases from 600 r/min to 800 r/min, the abrasion rate increases. However, the abrasion rate does not change significantly when the rotation speed is further increased. The abrasion rate of samples with 40 or 45 phr CB is similar, but when 50 phr CB is adopted, the wear resistance of sample is significantly improved. Observation on the abraded surface and the wear debris reveals that sticky degradation layers appear on the rubber surface, and micrometer sized fine-grained wear debris and large-sized crimped wear debris are simultaneously included in the wear debris, indicating that the abrasion resistance of NR-TPI composites mainly depends on the dynamic cycle of the two processes, the degradation of surface layer and the peeling of degradation layer. Particle wear mainly occurs when the former is dominant, while roll-up wear becomes the dominant wear mechanism when the latter is dominant. The effects of load and rotation speed on abrasion resistance are essentially achieved by affecting these two processes.