VGCF填充PVDF/PMMA复合材料导电性能的研究

Study on Electrical Conductivity of VGCF Filled PVDF/PMMA Composite

以气相生长碳纤维(VGCF)为导电填料,聚偏氟乙烯(PVDF)、聚甲基丙烯酸甲酯(PMMA)为基体制备复合型导电高分子材料。考察了填料用量、基体种类、配比以及PVDF结晶行为对复合材料导电性能的影响。结果表明,VGCF填充PMMA、PVDF、PVDF/PMMA(50/50)体系的渗滤阈值分别为5、4、3phr的填料用量。VGCF的加入会导致PVDF/PMMA体系发生微观相分离,而且VGCF会选择性富集在PVDF的非晶相中,所以PVDF/PMMA/VGCF体系的导电性呈现双重渗滤现象,该体系的体积电阻率不仅取决于富集相中VGCF的含量,而且还与PVDF相的连续性及其结晶行为密切相关。

Taking vapor grown carbon fiber （VGCF） as a conductive filler, Poly （vinylidene fluoride） （PVDF）, Poly（methyl methacrylate） （PMMA） and PVDF/PMMA blends as matrices, conductive polymer based composites were prepared. The effects of filler content, polymer types, matrix ratio and PVDF crystallization behavior on the electrical conductivity of the composites were studied. The results showed the percolation thresholds of VGCF filled PMMA, PVDF, PVDF/PMMA （50/50） composites were 5, 4 and 3 phr filler content, respectively. The addition of VGCF could induce the micro-phase separation of PVDF/PMMA blends, and VGCF was preferentially located in the PVDF amorphous phase, resulting in a double percolation phenomenon for PVDF/PMMA/VGCF composite. The volume resistivity of the system not only depended on the VGCF content in PVDF amorphous phase, but was also related to the continuity of PVDF phase and its crystallization behavior in the composite.