WEAR OF NATURAL-RUBBER AND STYRENE-BUTADIENE RUBBER VULCANIZATES AT ELEVATED-TEMPERATURES

The effect of carbon black loading, testing temperature and ageing on the abrasion loss (V), dynamic coefficient of friction (mu) and frictional force (F) of natural rubber (NR) and styrene-butadiene rubber (SBR) vulcanizates is reported. The value of V increases with temperature in spite of decreasing mu and F. After ageing, V of gum SBR is less than that of unaged samples due to resin formation. The value of V decreases with carbon black loading. The abradability (A) is related to the reciprocal of breaking energy (E(b)) by A = C/E(b), where C is a constant having value of the order of 10(-12) m3. Ridges are observed on the abraded surface of NR and SBR. The ridge spacing decreases with carbon black loading and increases with testing temperature. The abrasion loss increases linearly with ridge spacing.