Аннотация
This study examines the usage of natural zeolite as a substitute for silica in rubber compounds used for hydraulic sealing. Zeolite was modified by acid activation followed by thermal treatment to enhance its surface properties and structural stability. X-Ray Fluorescence (XRF) analysis revealed an increase in the SiO₂ content to up to 60.4 wt% after modification. Scanning Electron Microscopy (SEM) demonstrated a more uniform particle morphology, while Fourier Transform Infrared (FTIR) spectroscopy confirmed that the aluminosilicate framework was preserved. Rubber compounds based on synthetic isoprene (SKI-3) were prepared by replacing 5–20 phr of silica with the modified zeolite while maintaining constant filler loading. Increasing the zeolite content slightly decreased Mooney viscosity (from 44 to 41 MU), indicating improved processability. Tensile strength decreased moderately, from 13.54 MPa to 12.98 MPa, remaining within the required industrial specification of ≥12 MPa. Elongation at break increased, and tear resistance remained above the acceptable limit, showing that modified natural zeolite can be used as a functional mineral filler in sealing elastomers without significantly deteriorating key performance properties. Up to 20 phr of precipitated silica can be replaced while maintaining compliance with industrial requirements, offering a cost-effective, sustainable alternative for rubber compound formulation.