Dielectric Properties Of SiC/ZnO/EP Micro-nano Composite Materials

Epoxy resin(EP)is widely used in the field of electrical insulation due to its excellent electrical insulation properties.With the construction of UHV power grids and the development of materials science,the demand for electrical insulation properties of conventional epoxy resins is increasing.Pure epoxy resin needs to be improved in terms of preventing breakdown,increasing flashover voltage,preventing corona,etc.In order to meet the needs of life and production,by adding inorganic micro and nano particles to the polymer to improve the originality of some polymers Performance,thus guiding the research direction in the field of dielectric materials.In this paper,epoxy resin is used as the matrix,micron silicon carbide and nano zinc oxide are used as fillers,and different proportions of epoxy resin based micro,nano and micro-nano composites are prepared by melt blending method combined with ultrasonic vibration in 80 ? water bath At the same time,the SEM image is used to characterize the microstructure of the composite sample,and the electrical insulation properties of the epoxy resin and its composite material are studied through a series of experiments,such as DC conductivity,AC breakdown electric field strength,and dielectric spectrum and dielectric.Electric temperature spectrum,etc.Breakdown experiments show that the combination of microparticles at room temperature reduces the breakdown electric field strength of epoxy resin by about 7.7%,while the nanocomposite increases the breakdown electric field strength of epoxy resin by about 5.2%.The variable field conductance experiment shows that the nonlinear coefficient of pure EP basically maintains a certain value before the threshold field strength,which is 0.08,and the nonlinear coefficient increases to 0.87 after the threshold field strength;The linear coefficients are maintained between 1.6 and 2.The variable temperature conductivity experiment shows that when the temperature is lower than 80 ?,The conductivity of pure EP and its composite materials increases slowly,and the activation energy of pure EP is 2.17 KJ / mol.When the temperature increases above 80 ?,the conductivity of pure EP and its composite materials surges,of which Recombination facilitates the formation of conductive channels in EP.The dielectric spectrum shows that the relative dielectric constant of EP and its composites decreases with increasing frequency,the dielectric constant of composites at different frequencies remains between 3.5 and 4.5,and the loss tangent value varies with frequency.The increase first decreases and then increases,but its value remains below 0.3;The dielectric spectrum shows that the relative dielectric constant of EP and its composites increases with increasing temperature,and the dielectric constant of nanocomposites increases the most,from 4.0 to 5.0,and the loss tangent also increases with temperature.The increase is increased by the increase of the composite material,and the increase of the composite material is the largest,the maximum increase can reach 0.1,but its value is kept within 0.12;the doping of inorganic micro and nanometers increases the dielectric constant of epoxy resin but also increases Material loss.