Nanocellulose-enabled sustainable reinforcement of nitrile butadiene rubber: A comprehensive review

The increasing global emphasis on sustainable materials is driving a transition within the rubber industry from conventional petroleum-derived polymers to renewable, bio-based alternatives. This review critically assesses the development of high-performance nitrile butadiene rubber (NBR) bionanocomposites reinforced with nanocellulose, a biodegradable nanofiller with high aspect ratio and excellent mechanical properties. Despite its potential, nanocellulose's inherent hydrophilicity limits its compatibility with hydrophobic NBR, thereby restricting reinforcement efficiency. To overcome this limitation, the review systematically evaluates key surface modification strategies, including silylation, ionic liquids, and deep eutectic solvents, to enhance interfacial adhesion within NBR matrices. The review further examines the roles of mechanical dispersion, compounding, and processing techniques in achieving uniform nanocellulose distribution. By synthesizing the state of the art, this work elucidates structure–property relationships and outlines strategies to address challenges such as agglomeration. Overall, this review provides a strategic foundation for designing next-generation, sustainable NBR bionanocomposites that advance high-performance green rubber technologies.