Effect of Carbon Nanofillers on the Properties of Rubber Composites With High Levels of Carbon Black and Silica

ABSTRACT High‐performance rubber‐based composites often contain significant amounts of fillers such as carbon black and silica. Improving the behavior of such composites with small amounts of nanomaterials remains a challenge, and limited progress has been reported in recent years. A critical step in this modification is to achieve uniform dispersion of the nanomaterials within the composite. In this study, carbon nanotubes (CNTs) and reduced graphene oxide (RGO) were pre‐dispersed in sulfur using an innovative method and then incorporated into a commercial rubber. The quality of the synthesized nanomaterials and their interaction with sulfur were evaluated using scanning electron microscopy, Raman spectroscopy, and thermogravimetric analysis. CNTs and RGO nanoplatelets were deposited on the sulfur particle surfaces, achieving extensive coverage. The nanocomposites showed increased crosslink density. The reduced minimum torque observed for these materials compared to rubber suggests a potential lubricating effect of carbon nanomaterials during processing. Mechanical tests revealed the significant impact of the nanomaterials: tear strength increased by 22% in the rubber/CNT nanocomposite, while resilience improved by approximately 20% in all nanocomposites. Contact angle measurements showed a reduction in surface wettability of the nanocomposites compared to rubber after wear, a property that offers potential advantages in applications requiring improved hydrophobicity and durability.