Effect of carbon black properties on the abrasion resistance of rubber compounds at low sliding speed

The effect of carbon black (CB) structure and surface area on abrasion resistance at low sliding speeds was studied using a custom-built surface contact abrasion machine. Natural rubber compounds containing five different CBs at equivalent particulate volume fractions were examined. Increasing CB structure increases the abrasion resistance by imparting higher incremental modulus, which most likely minimizes the interaction of specimen with the abrading substrate and thus reduces the tearing energy on the specimen. Increasing CB surface area increases the abrasion resistance most likely by increasing the viscoelastic energy dissipation, which typically toughens the elastomer. Molecular weight measurements indicate similar to 80% reduction in the length of polymer chains from their initial uncured length following abrasion. The formation of smear wear, which acts as a protective viscous layer, significantly reduces the abrasion loss.