Influence of Zinc Oxide Loaded Sepiolite Wet Process on the Properties of Natural Rubber Composites

ABSTRACT Conventional zinc oxide use in rubber vulcanization poses environmental hazards due to ecotoxic leaching. To address this, we developed sepiolite as a sustainable carrier for zinc oxide nanoparticles via chemical precipitation in aqueous suspensions. Successful deposition of crystalline zinc oxide nanoparticles (20–30 nm) on sepiolite fibers and formation of a stable zinc oxide loaded sepiolite suspension were determined by x‐ray diffraction, Fourier Transform infrared spectroscopy, x‐ray photoelectron spectroscopy, Scanning Electron Microscope, and Transmission Electron Microscope characterization. Natural rubber composites prepared by wet‐mixing zinc oxide loaded sepiolite masterbatches exhibited significantly enhanced zinc oxide dispersion versus conventional dry‐mixed zinc oxide unloaded sepiolite natural rubber composite material. Due to the improved dispersion of zinc oxide, the zinc oxide loaded sepiolite natural rubber composites system exhibited excellent crosslink density and mechanical properties, where sepiolite loading with 20% zinc oxide content enhanced the crosslink density by 9.1% and tensile strength by 6.2% compared to the unmodified blend, while we found that by optimizing the dispersion and activation efficiencies, the sepiolite‐loaded zinc oxide could reduce the zinc oxide addition by 40% while enhancing the mechanical and dynamic properties of NR composites. This approach provides an eco‐friendly route to the production of high‐performance rubber materials.