Effect of Exfoliated, Oxidized Molybdenum Disulfide on Mechanical and Tribological Properties of NBR / BR Blends

ABSTRACT Enhancing wear resistance is crucial for improving the durability of rubber products while minimizing the release of rubber particles into the environment. Molybdenum disulfide (MoS ₂ ) is a promising reinforcing filler, but the tendency of its sheets to stack together limits dispersion within rubber matrices. To overcome this challenge, we present a straightforward method for liquid‐phase exfoliation and partial oxidation of MoS ₂ using CaCl ₂ and H ₂ O ₂ , assisted by ultrasonication. The successful exfoliation–oxidation process is confirmed through multiple characterization techniques, all complementing each other. The effects of virgin MoS ₂ (M) and exfoliated, oxidized MoS ₂ (MO) on swelling behavior, mechanical performance, tribological properties, and thermal stability of an NBR/BR blend are systematically analyzed. MO sheets exhibit superior dispersion, effectively reducing wear‐induced weight loss from 15.2% in the pristine blend to 9.9% at a 4 phr MO loading. Additionally, incorporating 4 phr MO into the blend substantially enhances crosslink density (261%), tensile strength (96%), tear strength (70%), and thermal stability (63% increase in residual mass at 700°C). Notably, while adding M to the blend system enhanced these properties, the improvements were relatively lower in magnitude. These findings offer a promising approach to developing multifunctional rubber nanocomposites for industrial applications.