Study on hydrophobicity and aging characteristics of epoxy resin modified with nano-MgO

The 10 kV switchgear is widely utilized in power systems due to its convenience and reliability. However, in high-humidity environments, switchgear is susceptible to condensation, which can severely damage its internal insulation components. To address this issue, this study modifies epoxy resin (EP) by incorporating nano-MgO to improve its hydrophobic properties. Initially, molecular dynamics simulations were conducted to determine the optimal doping ratio of nano-MgO by evaluating modified materials with varying concentrations. MgO/EP composites were then synthesized with nano-MgO doping levels of 1, 5, 10, and 15 wt%, and their hydrophobic and electrothermal properties were assessed. Following this, a thermal aging test was performed to evaluate the long-term performance of the composites. The findings demonstrate that the addition of nano-MgO enhances the hydrophobicity, thermal conductivity, and insulating properties of the EP. Specifically, as the concentration of nano-MgO increases, both the contact angle and thermal conductivity of the composites improve, while the volume resistivity first increases and then decreases with higher nano-MgO content. Nonetheless, all composites consistently outperform pure EP. Throughout each aging stage, the contact angle, thermal conductivity, and volume resistivity of the nano-MgO-modified EP remain superior to those of the unmodified EP.