Study On Insulation Properties Of Epoxy Resin Filled With Nano-TiO₂ Modified By Plasma Fluorination

With the continuous development of UHV transmission and smart grid,the reliability of high voltage electrical equipment is required to be higher.Due to the application of epoxy resin in high voltage transmission project,its performance needs to be further improved.In this paper,coupling agent and low pressure plasma fluorination were used to treat nano-TiO₂,and the treated nano particles were filled into epoxy resin to study the insulation properties of the composite.Firstly,nano-TiO₂ was treated by coupling agent and plasma fluorination.The results show that the fluorine content on the surface of nano-TiO₂ can be increased to 7.57%after synergistic modification.Secondly,TiO₂/EP composites with different filling ratios were prepared and their insulation properties were analyzed.The experimental results show that the initial partial discharge voltage and breakdown field strength are increased by 79.5%and 89.5%,DC flashover voltage is increased by 16.7%,volume resistivity and surface resistivity are increased by 48.5%and 177.5%,dielectric constant and dielectric loss are reduced by 9.6%and 83.3%,respectively.Finally,the composites were subjected to UV aging.The results show that when the filling amount is 3%and the aging time is 15 days,the volume resistivity and surface resistivity of the composite are increased by 10.1%and 16.9%,and the dielectric constant and dielectric loss are reduced by 13.4%and 19.4%respectively.The results show that coupling agent combined with plasma fluorination of TiO₂ can improve the agglomeration of nanoparticles,the introduction of fluorine can significantly improve the insulation ability of the composite,and the addition of nano-TiO₂ can shield ultraviolet light and prevent the fracture of chemical bond,thus improving the anti ultraviolet aging performance of the composite.