发泡倍率对EVA/CB复合材料导电性能的影响

Effect of Foaming Fatio on the Conductivity of EVA/CB Composite

利用熔融共混-模压法制备了以乙烯-乙酸乙烯酯共聚物(EVA)为基体,炭黑(CB)为导电填料,热膨胀微胶囊(TEMs)为发泡剂的EVA/CB导电泡沫复合材料。利用扫描电子显微镜(SEM)研究了发泡剂含量对EVA/CB泡沫复合材料泡孔形态的影响,采用ZC36型高阻仪测试导电泡沫复合材料的体积电阻率,研究了发泡倍率对导电泡沫复合材料导电性能的影响。研究结果表明,随着热膨胀微球含量的增加,EVA/CB导电泡沫复合材料的泡孔的形状逐渐由圆形变为规则的多边形结构,泡孔的平均直径约为20μm且基本保持不变。当热膨胀微球含量由0份增加至7份时,EVA/CB导电泡沫复合材料的发泡倍率由1倍增大至3倍,电阻率呈先降低后上升的趋势,当发泡倍率升至1.69倍时,复合发泡材料的电阻率出现最低值为3.26×10^(7)Ω·cm;当发泡倍率增大至3倍时,EVA/CB复合发泡材料的电阻率增大至最大值,其值为7.02×10^(8)Ω·cm,可以为开发具有优异导电性能和轻质化的复合材料提供参考。

In order to prepare EVA/CB conductive foam composite,ethylene-vinyl acetate copolymer( EVA) as matrix,carbon black( CB) as conductive filler and thermal expansion microcapsules( TEMs) as foaming agent were mixed by melt blending and molding. The effect of foaming agent content on the morphology of EVA/CB foam composite were studied by using scanning electron microscope( SEM),the influence of foaming ratio on the conductivity of conductive foam composite was studied by ZC36 high resistance instrument by measuring the resistivity of foam composite. The research results showed that as the content of TEMs increased,the cells of EVA/CB conductive foam composite gradually change from round to regular polygonal forms,and the average cell diameter was about 20 μm and remained basically unchanged.As the content of thermal expansion microspheres increased from 0 to 7 phr,the foaming ratio of EVA/CB conductive foamed composite increased from 1 to 3 times and the resistivity of EVA/CB conductive foam composite decreased first and then increased. When the foaming ratio increased to 1. 69 times,the resistivity of conductive foam composite was the lowest at 3. 26 × 10^(7)Ω·cm. As the foaming ratio further increased to 3 times,the resistivity of EVA/CB composite foaming materials was the maximum at 7. 02 × 10^(8)Ω·cm,which provided reference for the development of composite materials with excellent electrical conductivity and light weight.