Synergetic enhancement of the electrical-thermal-mechanical properties of EPDM composites modified by Kaolin and BNNSs

Offshore wind power is clean energy with rapid growth in recent years. As a key part of wind turbines, improving the combination performance of wind turbine cable insulation has a crucial impact on the development of wind power systems. In this paper, kaolin is selected to improve the tensile strength of Ethylene-Propylene-Diene Monomer (EPDM) rubber, and Boron Nitride Nanosheeets (BNNSs) with good electrical insulation and thermal conductivity are co-doped into kaolin/EPDM to improve the breakdown strength and thermal conductivity of the composite. The results show that the properties of the composites are improved when the powders are doped into EPDM. When the kaolin doping amount is 30wt%, the dielectric properties and the mechanical properties are improved, but the breakdown strength has deteriorated. Based on 30wt% kaolin content, BNNSs are added to EPDM. The breakdown strength is improved. The breakdown strength of the 30wt% Kaolin/5wt%BNNSs co-doped EPDM is 83.33 kV/mm. In addition, due to the synergistic effect between the two powders, the tensile strength of the composite is increased to 8.06 MPa. Meanwhile, with the increase of BNNSs, the thermal conductivity of composite is improved. It increases to 1.247 W/(m⋅K) This work has important guiding significance for improving the combination performance of the wind turbine cable insulation.