The Comparative Study Of Electrical Properties And Responsive Behaviors In Different External Fields Of CB/PP And CNTs/PP Conductive Polymer Composites

The investigation and exploitation of conductive polymer composites (CPCs) is one of the hot issues for the functionalization of polymers for a long time. CPCs are prepared by filling one or several kinds of conductive fillers into the one or several polymers. CPCs have been widely used for as antistatic materials, self-regulated heaters, electromagnetic shielding, sensors and detection systems, etc. In recent years, CPCs have received great attention due to their popular applications in many fields, especially for the sensitive stimuli-response behaviors under extension, compression and organic solvent, Based on the description above, basic investigation of CPCs has been studied. Although, the effect of own different dimensions conductive fillers on electrical property of CPCs has not been cleared fully, which is crucial for the applications of CPCs. In this paper, we prepared the CPCs by filling CB (0dimension) or CNTs (1dimension) into polypropylene by melt mixing method, the behaviour of percolation thresholds of both CPCs have been stutied. In the present work, the concentrations of CB and CNTs are7.16vol.%and3.41vol.%, respectively, which are little beyond the percolation thresholds of CNT/PP and CB/PP composites (ca.7.05vol.%and3.24vol.%, respectively). The variation of the electrical resistance of both CPCs under tensile field, stress-strain cycles with strain (ε<3%) and the comparison of the mechanical property and electrical property of both CPCs have been investigated. Then the mechanisms of electric conduction have been summarized. And the phenomena, which are observed, have been explained by mechanisms. Finally, a schematic illustration was drawn to illustrate the mechanism of the different sensing behaviour, micro-structure envolution of the inner of samples has been described directly and compared to the both CPCs under extra field.Following, we prepared CB/PP, CNTs/PP CPCs by compression in the vacuum environment, and decreased percolation thresholds remarkablely. In addition, the envolution of the electrical property of both CPCs, which have been prepared in two different conditions, under tensile field, cycle tension with strain (ε<3%) has been investigated. The electrical property of both CPCs with different preparation ways has been compared also.Then, in order to prepare stable CPCs, the samples have been annealed at the different temperatures (80℃,120℃) for three hours. The electrical resistance of annealed samples with samples of before annealed were compared. The variation of the electrical resistance of both CPCs, under tensile field, cycle tension with strain (ε≤3%) has been investigated. The electrical property of both CPCs with different preparation ways has been compared as well.Finally, the xylene stimuli-response behaviors of both CPCs have been investigated. It’s found that the responsivity of CB/PP is higher and the reproducibility of CNTs/PP is higher under10IDRs immersion-drying runs (5min immersion, then15min drying). Moreover, after some samples were immersed in xylene for72h, then absolute drying, the effect of immersion on the responsivity and reproducibility under10IDRs immersion-drying runs have been studied. In addition, the organic liquid (cyclohexane and carbon tetrachloride (CCl4), stimuli-response behaviors of both CPCs have been observed.