Improvement of Resistance to Electrical Tree in LDPE by Mixed Addition of Nano-Particles and Azobenzoic Compound

为提高LDPE在交流电压下的耐电树枝性能，采用偶氮化合物与纳米Al_2O_3粒子混合加入的方法制备了聚合物纳米复合材料。实验结果表明，混合添加提高了树枝的起始电压。混合加料的增加比例取决于偶氮苯化合物的种类。当复合氧化物和Al_2O_3的质量分数分别为2.0wt%和3.0wt%时，增重率最高，为300%。混合添加剂对控制树木发育也是有效的，特别是在其孵化过程中。混合添加的潜伏期是不添加任何添加剂的样品的2000倍。然而，控制效果与化合物的浓度和外加电压的大小有很大关系。

The Polymer nano-composite was prepared by mixed addition of azobenzoic compound and Al_2O_3 nano-particle into LDPE to improve the electrical treeing resistance under ac voltage application. The experimental results showed that tree initiation voltage was increased by the mixed addition. The increasing ratio for the mixed addition depends on the kind of azobenzoic compound. The highest increasing ratio of 300% was obtained in the mixed addition of the compound and Al_2O_3 at the concentrations of 2.0 wt% and 3.0 wt%, respectively. The mixed addition was also effective for control of tree development especially in its incubation. The incubation period of the mixed addition was2000times longer than that for the specimen without any additive. However, the control effect depended significantly on the concentration of the compound and magnitude of applied voltage.