Design of nanoclay and carbon black reinforced NR/SBR composites for high performance power transmission belt applications

The dependence of the carbon black (CB) industry on fossil fuels has prompted rubber manufacturers to explore sustainable filler alternatives that align with modern environmental priorities. Among these, nanoclay (NC) has emerged over recent decades as a promising candidate due to its superior mechanical reinforcement and morphological advantages. However, its widespread adoption has been hindered by challenges such as poor dispersion within polymer matrices. In this study, the impact of hybridizing NC with CB on the curing, mechanical, and morphological properties of natural rubber (NR)/styrene-butadiene rubber (SBR) blends was experimentally investigated for potential industrial applications. Composites were prepared by partially replacing CB with varying NC loadings (5, 10 &15 phr), and their morphology was analysed using XRD and transmission electron microscopy (TEM). Results confirmed the formation of dispersed and intercalated nanostructures at 5 and 10 phr NC loading. The curing properties revealed a 15% reduction in cure time and a 20% decrease in maximum torque with NC incorporation. Notably, tensile strength improved by 15% at 10 phr replacement. Compression set and abrasion resistance also shows an increment at 10 Phr loading. So, the results show that optimum compound properties were obtained at 10 Phr and above that agglomeration starts and a reduction in physical properties were noticed.