Influence of carbon nanotube on the abrasion and crack growth behaviors of styrene-butadiene rubber compounds

Abstract

In this study, the influence of carbon nanotube (CNT) on the wear and crack growth behaviors of styrene-butadiene rubber (SBR) vulcanizates was reported. Two types of carbon black (CB)-filled SBR compounds were prepared with a total filler loading of 50 phr. In each case, a small fraction (~3 phr) of CB was replaced either with pristine CNT (p-CNT) or with surface-modified CNT (T-CNT). The surface modification of CNT was carried out using a silane coupling agent (Si-69). Wear resistance and crack growth behaviors were evaluated by using a blade-type abrader and a dynamic fatigue instrument, respectively. The SBR containing p-CNT exhibited reduced wear resistance, as the unmodified CNT was more easily pulled out by the blade during abrasion. On the other hand, the SBR containing T-CNT demonstrated improved wear resistance (1phr of T-CNT: 6-7.5% improvement), attributed to the enhanced interaction between CNT and the SBR matrix facilitated by the silane coupling agent, which reduced the amount of CNT pull-out. Crack growth resistance was improved in both SBR containing p-CNT (7.1-60.6% improvement) and T-CNT (39.8-71.8% improvement). This enhancement is explained by the gradual and partial pull-out of CNT under repeated straining, which contributed to energy dissipation and improved fatigue resistance, even in the absence of surface modification.