| Epoxy Resin(EP)is the main insulation material for electrical equipment,with strong insulation,good adhesive layer and other advantages,has received a lot of attention from scholars at home and abroad.However,in practical applications,EP curing compounds have disadvantages such as poor heat resistance and easy cracking,which restrict their further application in engineering,and new technologies are urgently needed to enhance the application efficiency of EP.In this study,based on the EP preparation process,a method of plasma fluorination of ZnO nanoparticles was proposed,and composites with different filling amounts of fluorinated modified ZnO/EP were prepared by means of physical blending,and the aging characteristics and mechanisms of the composites were analyzed in depth.The following main studies were carried out:For the problem of easy agglomeration of nanoparticles in the filling process,the study of fluorinated modified nano-ZnO particles was carried out based on the plasma fluorination method.The results show that the fluorinated modified F elements are grafted on the nanoparticles in the form of-CF2,and the nanoparticles are uniformly dispersed,which effectively fill the defects of the rough EP surface.To address the problem of the inhibition effect of composites on electric dendrites,a study on the mechanism of electric dendrite growth of composites was carried out based on the method of simulating local electric field concentration by pressurizing the composites.It was found that the length of the electric dendrite of the fluorinated modified composites was 0.02-0.04mm shorter than that before the fluorination modification,indicating that the nanoparticles could introduce deep traps in the epoxy resin and could effectively inhibit the generation of electric dendrites.By observing the characteristic parameters such as electric dendrite length,dendrite width,expansion coefficient,degradation area and growth rate of the composites,it was found that the best inhibition of electric dendrite growth was achieved when the filling amount was 7 wt%.The study on the effect of modified ZnO nanoparticles on the electrical properties of EP after combined thermal-UV aging was carried out to investigate the law and mechanism of combined thermal-UV aging of the composites.It was found that the aging showed a progressive damage pattern,and the composite with a filling amount of 3 wt%had the most obvious effect of resistance to combined thermal-UV aging.And after 30 days of aging,the breakdown field strength of the fluorinated modified composites was 18.42%higher than that of the pure epoxy resin.In summary,the dispersion of ZnO nanoparticles treated by plasma fluorination grafting was improved,and the surface modification of epoxy resin was better,which could effectively inhibit the growth of electric dendrites and enhance the combined thermal-UV aging electrical properties of the composites.Although the inhibition effects of the composites with different filling amounts in different aging environments are different,they all contribute to the improvement of the electrical properties of the insulation materials after aging,which provides theoretical basis and technical support for the further landing application of EP in electrical engineering. |
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