The present investigation is dedicated to the impact of replacing conventional zinc oxide (ZnO) with nano-zinc oxide (nZnO) in ethylene-propylene-diene monomer (EPDM) rubber compounds. Multiple rubber compounds were prepared utilizing conventional and nano-zinc oxides, followed by vulcanization employing a semi-efficient vulcanization system (SEV). Results indicate that nZnO promotes a more uniform dispersion within the rubber matrix compared to ZnO. Moreover, the incorporation of nZnO enhances the vulcanization process, yielding a notable 27% increase in crosslink density. Nevertheless, the mechanical properties of the cured rubber, encompassing tear strength, hardness, tensile strength, and elongation at break, remained either unaffected or exhibited slight deterioration. This observed discrepancy is ascribed to the inherent tendency of nZnO particles to self-aggregate, thereby disrupting the homogeneous distribution of the activator within the rubber matrix and fostering the formation of localized crosslink networks around the nanoparticles. To overcome this challenge, the study proposes potential strategies, including nanoparticle surface modification, optimization of mixing parameters, and integration of compatibilizers, aiming to enhance the interaction between nZnO and rubber chains, mitigate agglomeration, and facilitate a more even dispersion. The study suggests the potential of nZnO in augmenting the crosslinking efficiency of rubber compounds while emphasizing the imperative need to address nanoparticle agglomeration to optimize overall mechanical properties.

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