Enhancing electrochemical degradation resistance in EPDM/CB composites: A comprehensive approach to achieve optimal physico‐mechanical properties for automotive applications

Abstract

In the present study, a peroxide‐cured ethylene propylene diene monomer (EPDM) rubber composite with a non‐conductive path achieved through the use of a special‐grade carbon black, resistant to electrochemical degradation, for automotive applications, especially in the manufacturing of radiator coolant hoses, has been developed. The most significant aspect of this study is that the developed composite exhibits optimized physico‐mechanical properties such as hardness, tensile strength, elongation at break, and compression set, along with considerable thermal stability and cold flexibility. Both sulfur‐cured and peroxide‐vulcanized EPDM composites were prepared, and the final validation of the composite was obtained through a comprehensive comparison of these properties. The composite's stability was confirmed through heat aging measurements and glycol‐water coolant immersion tests. Furthermore, the thermal behavior of the composite was analyzed using thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The novel composite was characterized through Fourier Transform Infrared Spectroscopy (FTIR) studies, and its surface morphology was examined via Field Emission Scanning Electron Microscopy (FE‐SEM). The cold flexibility crack formation test was conducted in accordance with ASTM D 2137, and the electrochemical degradation (ECD) resistance test was carried out following SAE J 1684 method 2. The results indicate that the developed composite remained free from crack formation during these tests.Highlights Novel EPDM composite resists ECD in radiator hoses. Optimized physico‐mechanical properties achieved. Thorough validation of sulfur versus peroxide curing. Successful prevention of crack formation. Comprehensive analysis: TGA, DSC, FE‐SEM, FTIR.