为了研究聚合物/无机微纳米复合物的耐电树枝性能,采用熔融共混法制备了环氧树脂/二氧化硅/蒙脱土(EP/SiO_2/MMT)微纳米复合材料,利用针–板电极系统同时配合数字摄像系统对纯EP及其复合材料试样进行电树枝引发并记录树枝的生长过程以及形貌特征,对比研究了4种试样的起树率、电树枝发展过程、电树枝长度、扩展系数和形态特征。实验结果表明:与纯环氧树脂相比,微米复合材料和微纳米复合材料起树率较低,而纳米复合材料和微纳米复合材料电树枝长度较短,在所研究的4种试样中,微纳米复合材料具有最大的扩展系数。利用景深合成技术,获得了环氧树脂及其复合材料中电树枝的叠层立体图像和电树枝通道细节,据此建立了EP/SiO_2/MMT微纳米复合材料电树枝发展的模型。
In order to study the performances of electrical tree resistance for polymers/inorganic micro-nano particles composites, various kinds of EP/SiO_2/MMT micro-nano composites were prepared by the melt blending method. Specimen with needle-plate electrode and digital camera system were used to observe and record the initiating and propagating process of electrical trees in pure EP and its composite. The ratio of emerging electrical treeing, length of electrical tree growth, expansion factor, and morphology characteristics in various samples were investigated, respectively. The experimental results show that the ratio of emerging electrical trees in micro composite and micro-nano composite are lower, however the electrical tree length in nano composite and micro-nano composite is shorter compared with that of the origin EP. The micro-nano composite material exhibits the largest expansion coefficient among the 4 kinds of samples. The stereoscopic image in lamination and detail of the electrical treeing in EP and its composites were obtained by means of the focus stacked method, and the propagation pattern of electrical tree in EP/SiO_2/MMT micro-nano composite is modeled.