Research On Conductive Thermoplastic Composites

Conductive composites, a sort of advanced functional conductive composites, have been widely used in many fields of national economy. With the continuous progress of science and technology, conductive composites have gradually expanded to many high-tech fields, such as aviation and military industry. As these areas have more and more requirements for conductive composites, a large number of researchers have tried to develop various kinds of conductive composites with higher conductivity and stable mechanical properties to meet the requirement of high conductive areas.The paper used two new kinds of conductive fillers—nickel-coated carbon fiber and nickel-graphite powder. The filled conductive composites were prepared by adding nickel-coated carbon fiber/nickel-graphite powders into PC/ABS, and the conductive composites was made using extrusion cable coating process. The influence of the conductive filler content, particle length, screw speed, packing pressure and coupling agent on the conductivity and mechanical properties of the composites was systematically studied. In the study above, microscopic structures of distributed conductive fillers in resin was analyzed to study the influence of related factors on conductive mechanism of composites. The specific content and results are as follows:1、During the preparation of conductive composites, the influence of the two kinds of conductive fillers on the volume resistivity (conductivity) and mechanical properties of composites was studied and analyzed by changing conductive filler content. Simultaneously, the influence of particle length on the conductivity was studied. The results showed that the conductivity and mechanical properties of composites increased with raising NiCF content. However, with raising nickel-graphite powders content, the conductivity increased and the mechanical properties decreased.2、The influence of packing pressure, injection pressure and screw speed on the conductivity of the composites was studied and analyzed. Finally, The results showed that the conductivity of the composites was optimum(the volume resistivity was 1.15Ω·cm), when the screw speed, injection pressure and packing pressure was 140r/min、85MPa and 64MPa respectively.3、The influence of NiCF treated with coupling agent KH560 on the volume resistivity and mechanical properties of composites was studied and analyzed. The results showed that the NiCF treated with coupling agent could partly affect the conductivity of composites only at the appropriate molding process conditions, but it didn’t have obvious effect on the mechanical properties of the composites at this experimental condition.