中文摘要：

为研究纳米ZnO掺杂对环氧树脂复合材料绝缘特性的影响,以纳米ZnO改性双酚A型环氧树脂材料为研究对象,考察了不同掺杂量下复合材料直流电导、介电常数等绝缘特征参数的变化趋势;并利用针板电极系统,分别对ZnO/环氧和SiO_2/环氧复合材料进行了起始局放电压对比测试。研究发现,当纳米ZnO质量分数〉15%时,复合材料开始呈现非线性电导特性,复合材料介电常数也发生显著变化,质量分数为30%时其电导非线性系数可达到18.7,介电常数则可上升至5.9。相同电极结构下,纳米ZnO/环氧复合材料的起始局放电压显著高于SiO_2/环氧复合材料,ZnO质量分数为15%时起始局放起始电压达到最大值,分别比无掺杂树脂及纳米SiO_2掺杂树脂提高了33%和22%。研究表明,纳米ZnO粒子的引入显著提高了环氧树脂复合材料的绝缘性能,纳米ZnO粒子的界面效应和非线性电导特性在改善复合树脂绝缘特性方面发挥了主要作用。

英文摘要：

To investigate the improvement effect of nano-ZnO modification on epoxy composites, the bisphenol A epoxy resins were doped with 50-nm ZnO and their DC conductivities and dielectric constants were measured. The partial discharging tests of these modified epoxy resin samples were also carried out under the needle-plan electrodes. Meanwhile, the effects of nano-ZnO doping level on the modified epoxy resin dielectric characteristics were evaluated and the mechanism leading to this modification was also discussed. The experimental results show that modified composites doped with above 15% nano-ZnO exhibit remarkable nonlinear conductivity properties. The value of nonlinear DC conductivity can be increased to 18.7 by 30% doping level, and the dielectric constants can reach 5.8. By comparing the experimental results of nano-ZnO and the results of nano silicon dioxide of the same particle size, it can be found that the initial discharging voltage of epoxy composite modified with ZnO is significantly higher than that of SiO_2 doping sample. At 15% doping level and under the same testing electrodes, the initial discharging voltage of epoxy resins modified with nano-ZnO reaches its highest value which is 33% higher than that of unmodified samples and 22% higher than that of SiO_2 doping samples. The research shows that the nano-ZnO doping treatment can greatly change epoxy resin composite dielectric parameters and remarkably improve its insulating properties, which is attributed to the interface effects and nonlinear conductivity of nano-ZnO.