Construction of a percolation zone for electrostatic discharge in EPDM/CB composites: A comprehensive mechanism to attain the optimum physico-mechanical properties

Electrostatic discharge (ESD) is a critical issue in the automobile industry. ESD can occur due to the rubbing of dissimilar materials, potentially damaging sensitive components. Automakers must use ESD protection to safeguard the reliability of the components. In this scenario, the automotive industries demand for suitable materials to address this problem. The present study focuses on the development of EPDM rubber composites with low-volume resistivity and optimized physico-mechanical properties, which are the vital parameters to be addressed in electrostatic discharge for automotive applications. EPDM rubber composites were cured by sulfur and peroxide with a special-grade conductive carbon black (CB). These composites were analyzed by Fourier Transform Infrared Spectroscopy (FTIR), Thermo gravimetric analysis (TGA), and Differential Scanning Calorimetry (DSC). The dispersion of conductive CB in the polymer matrix was examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The BET adsorption technique was employed to investigate the specific surface area and porosity of CB. The ESD behavior of the composites was evaluated by measuring the volume resistivity(ASTM D257). The Studies reveal that the developed material has moderate physico-mechanical properties and consistent thermal stability. Above all, the conductivity offered by the composite is adequate for ESD applications. Highlights: Developed sulfur-cured EPDM rubber composite with low-volume resistivity. Peroxide cured EPDM rubber has higher thermal stability than sulfur-cured one. Carbon black (CB) with a high surface area can easily form a conductive network. A good conductive network is formed at the percolation zone. The hardness of the EPDM composite increases with the loading of CB.