Design Of The Conductive Network In Conductive Polymer Composites And Its Effect On Electrical Properties

One of the major research challenges in the development of conducting polymer composite materials is reducing the filler content as much as possible while improving the electrical conductivity and the stability of electrical properties. In this field, the design of the electrical conductive network plays a key role. This dissertation focuses on the design of the electrical conductive network and studying on its influence of the electrical properties of composite.First, a new approach for the selective localization of filler at the interface of polymers phase was reported. This approach relies upon two aspects: the thermodynamically induced phase self-assembly in ternary polymer blends and the thermodynamically induced selective localization of filler in polymer phase. In CB or MCNT filled PMMA/EAA /PP composites, PP and PMMA form two continuous networks, while EAA incorporated with filler forms a continuous sheath structure at the interface of PP/PMMA. Thus, the conductive filler selectively locates at the interface of PP/PMMA. The filler content is reduced and the electrical conductivity is enhanced in both the CB or MCNT filled system.Quaternary composites consisting of two different types of filler and binary polymer were prepared by melt blending. The microstructure of the conductive networks and the conductivity properties of composite were investigated. The results show that: the double-percolated networks, as well as the mutual bridging between carbon fiber and conductive polymer phase region improve the electrical conductivity and the stability of electrical properties. Besides, the NTC effect is also decreased.