Collaborative improvement of electrical-thermal-mechanical properties of kaolin-filled ethylene propylene diene monomer and mechanism analysis

With the rapid development of offshore wind power, large-capacity wind turbine generators have put forward higher electrical and mechanical performance requirements for the cable. In this paper, kaolin/ethylene propylene diene monomer (EPDM) composites are prepared to investigate the effect of kaolin content on the electrical properties, mechanical properties and thermal conductivity of EPDM composites. The results show that appropriate amount of kaolin could synergistically improve the electrical-thermal-mechanical properties of EPDM. The composite with 30 wt% kaolin content achieves the best performance. The breakdown strength of kaolin/EPDM composites increases by 13.47%–72.19 kV/mm compared with that before modification, and the volume resistivity increases from 10¹³ to 10¹⁵ Ω·cm after modification. In addition, with the doping of kaolin, the tensile strength of composites significantly improves by over 500%–6.97 MPa, and the thermal conductivity of the composite is slightly improved. This work has important guiding significance for the development of insulation materials for cables. Highlights: Kaolin in EPDM scattered more uniform after modification. The addition of kaolin improves the electrical-thermal-mechanical properties of the composite. Kaolin/EPDM composites have promising applications.