Dielectric Properties And Thermal Properties Of SiC/ZnO/EP Micro-Nano Composites

Epoxy resin(EP)is widely used in electrical equipment insulation,but the rapid development of high-voltage direct current transmission and electronic packaging has put forward higher requirements for epoxy resin performance.Single-performance materials are difficult to meet the requirements of use,and multi-functional rings Oxygen resin composites are gradually becoming a development trend.Therefore,inorganic micro-and nano-fillers are added to the epoxy matrix as the dispersed phase.The electrical and thermal properties of epoxy resin and its composites are studied to find good electrothermal properties.Epoxy resin composite.In this paper,acicular ZnO was prepared by hydrothermal method.The results of SEM and XPS showed that the prepared acicular ZnO has a diameter of about 1.5~3?m and a length of about 20~30?m.The micro-,nano-,micro-nano composites of pure EP and single and composite fillers were prepared by melt blending with needle-shaped ZnO prepared in the laboratory as micro-filler and granular nano-ZnO and SiC as nano-fillers.The SEM image characterizes the microstructure of the composite specimen.The?-E characteristic curve,DSC curve and thermal conductivity of epoxy resin and its composites were obtained experimentally.The comparison of micro-,nano-and micro--pure epoxy resins and single and composite fillers at different temperatures and frequencies Dielectric properties of nanocomposites.The experimental results of SEM images show that the inorganic filler is uniformly dispersed in the EP matrix without obvious agglomeration.When investigating the influence of filler type,content and ratio on the electrical conductivity of composites,it is found that the composites of three kinds of single fillers have similar electrical conductivity with field strength,and all increase with the increase of filler content,and the threshold The field strength moves to the low field;the conductivity of different composite samples is SiC5,ZnO5Z,ZnO5Q,EP in order from large to small;and the acicular ZnO/SiC/EP micro-nano composite under the same electric field strength The conductivity of the sample is significantly larger than that of the granular ZnO/SiC/EP nanocomposite.The dielectric temperature spectrum test results show that the introduction of inorganic fillers increases the?_r and tan?values compared with pure EP.In the range of 20°C~120°C,the?_r and tan?values of each sample remained basically unchanged.When the temperature reached 120°C,?_r and tan?began to increase rapidly.The test results of the dielectric spectrum show that the?_r of each sample decreases with increasing frequency,while tan?decreases with increasing frequency.The thermal performance test results show that the glass transition temperature of each sample is SiC5,EP,ZnO2Q&SiC3,ZnO2Z&SiC3,ZnO5Q,ZnO5Z in order of high to low.The introduction of acicular ZnO significantly reduces the glass transition temperature of the composite system.The introduction of nano-SiC and granular nano-ZnO has little effect on the thermal conductivity of epoxy.The introduction of acicular ZnO can significantly improve the thermal conductivity of epoxy resin.The effect of inorganic filler on the electrical conductivity and thermal conductivity of epoxy is combined.It is found that the influence of acicular ZnO on the conductivity and thermal conductivity of epoxy is significantly greater than that of granular ZnO.It can be considered that the introduction of acicular ZnO filler improves the matrix at the same time.The conductive and thermal conductivity properties have a significant effect.