纳米碳纤维掺杂量与取向对纳米碳纤维/乙烯-醋酸乙烯酯复合材料介电性能的影响  

Effect of Carbon Nanofibers Incorporation Concentration and Orientation on Dielectric Properties in Carbon Nanofibers/Ethylene-vinyl Acetate Copolymer Composites

作　　者：郑丽娜[1] 郝春成[1,2] 

机构地区：[1]青岛科技大学材料科学与工程学院,山东青岛266042 [2]西安交通大学电力设备电气绝缘国家重点实验室,陕西西安710049

出　　处：《青岛科技大学学报（自然科学版）》2012年第5期468-473,共6页Journal of Qingdao University of Science and Technology:Natural Science Edition

基　　金：国家自然科学基金项目(51077075);电力设备电气绝缘国家重点实验室资助项目(EIPE10207)

摘　　要：通过微波法化学镀镍对纳米碳纤维(CNFs)进行表面改性,采用熔融共混法将表面改性的CNFs与乙烯-醋酸乙烯酯(EVA)复合制备CNFs/EVA复合材料,在模压交联过程中对复合材料施加磁场,使表面镀镍的CNFs在复合材料基体中沿磁场方向取向;用场发射扫描电子显微镜(FE-SEM),透射电子显微镜(TEM)和X射线衍射仪(XRD)观察表面改性前后CNFs表面形貌和结构、复合材料内部微观结构及取向情况;用宽频介电谱仪与阻抗谱仪对复合材料进行介电谱测试,研究了CNFs的取向与掺杂量对复合材料介电性能的影响,并用四探针法测量复合材料的体电阻率。研究结果表明,掺杂量和是否取向对复合材料介电性能影响较大;CNFs掺杂质量分数为0.5%时,取向复合材料相对介电常数最低,施加磁场取向不会增加复合材料的介电损耗,少量掺杂即可大幅降低复合材料的体电阻率。The carbon nanofibers （CNFs） were surface-modifieated by microwave assis- ted chemical nickel plating. The CNFs/EVA （ethylene-vinyl acetate） composites were prepared by melt-compounding of the modified CNFs and EVA resin. The magnetic field was used during the moulding process and CNFs oriented along the magnetic field direc- tion. The morphology and structure of surface-modificated CNFs, microstructure and o- rientation of composites were analyzed by field-emission scanning electron microscopy （FE-SEM）, transmission electron microscopy （TEM）, and X-ray diffraction （XRD）. The dielectric properties of CNFs/EVA nanocomposites with different CNFs concentra- tion and orientation were tested by broadband dielectric spectrometer and impedance spectrometer and the volume resistivity of composites was measured by four-probemethod. It is found that CNFs incorporation concentration and orientation have evident effects on the dielectric property of the composites. When the CNFs incorporation con- centration was 0.5%（mass concentration）, the dielectric constant of the oriented com- posites was the lowest. The orientation of CNFs in EVA matrix did not increase the die- lectric loss of the nanocomposites. A little corporation could reduce the volume resistivi- ty of composites significantly.

关 键 词：聚合物基复合材料 乙烯-醋酸乙烯酯 取向 介电性能 纳米碳纤维 

分 类 号：TB332[一般工业技术—材料科学与工程]