Optimizing Mechanical and Electrical Performance in EPDM Composites for Spacer Dampers: A Balanced Approach via Carbon Black Ratio and Protective Waxes

Electrical overhead lines rely on spacer dampers to prevent bundled conductors from colliding during wind and ice events, but these devices often suffer from performance loss, displacement, mechanical failure, and material degradation over time. Since installation and replacement are dangerous, slow, and costly, improving the materials and design of spacer dampers is essential for long-term reliability. As it was studied in the previous article, the actual elastomer is sensitive to aging. Therefore, in this study, it was explored how different types of ethylene propylene diene monomer (EPDM), carbon black (CB), and waxes affect the properties of elastomeric composites. The results of the tensile test of three types of EPDM showed that the one with the highest ethylene content had the highest stress and elongation at break. The experiment changed the ratio of two types of furnace carbon black through a series of mechanical, electrical, and physical tests. It represented that increasing the amount of carbon black with a smaller size and higher surface area (N330) improved the stress and elongation at break of EPDM composites, but made it less conductive. For the swelling test, also observed that the insoluble fraction was the same for all samples; however, samples with more N330 tended to swell more, indicating a lower crosslink density. Additionally, examining the effects of five types of waxes on the mechanical properties showed that a balanced property can be obtained by adding the blend of microcrystalline and paraffin wax, in which elongation at break and 100% modulus increased slightly, and stress at break decreased marginally in comparison to that of the control sample. Upon aging, the blend of two waxes had much retention of stress and elongation at break upon aging which means that it was more effective in protecting materials.