High Damping and Improved Mechanical Properties of EPDM Composites With the Inclusion of Synthesised Polar Epoxidised EPDM

ABSTRACT The heightened development of power network infrastructure has necessitated enhanced performance requirements from rubber composites used in transmission lines. Ethylene propylene diene monomer (EPDM) rubber is the primary matrix component in many damping spacer rubber composites for these applications. However, due to flexible molecular chains, nonpolar structure, and poor compatibility with polar nano‐fillers, EPDM exhibits poor mechanical properties and unsatisfactory damping properties. This study investigated the modification of EPDM molecular chains by epoxidation to produce epoxidised ethylene propylene diene monomer (EEPDM) rubber. Subsequently, EEPDM was compounded with EPDM to create EEPDM/EPDM composites. The introduction of epoxy groups in EEPDM enhanced intermolecular interactions within the rubber composites, facilitating energy dissipation and improving damping performance under external cyclic loads through polar intermolecular interactions. Furthermore, the interaction between epoxy groups and silica improved silica dispersion within the composite. EEPDM/EPDM composites in a 40/60 ratio demonstrated significant improvements over EPDM composites, with an increase of 173.8% in 300% Modulus and 23.2% improvement in tensile strength. Additionally, elevated loss factors were observed within the 0°C–40°C temperature range for EEPDM/EPDM composites, indicating an enhanced damping performance.