Comparison between randomly distributed structure and 3D segregated structure in chlorinated polyethylene/MWCNT composites: electrical conductivity, mechanical property, flame resistance and rheological property

Conductive polymer composites have generated significant academic and industrial interests in recent years. The microstructure directly affects the performances of conductive polymer composites. In this study, two structures, i.e., randomly distributed structure and 3D segregated structure, were fabricated in chlorinated polyethylene/multi-walled carbon nanotube (CPE/MWCNT) composites via solution mixing and direct hot-pressing, respectively. The morphology, electrical conductivity, mechanical property, flame resistance and rheological property of two structures were comparative studied. The results showed that the conductive paths were easier to build in 3D segregated structure. The percolation threshold of randomly distributed structure (4.81 wt%) was 4.4 times higher than that of 3D segregated structure (1.09 wt%). The addition of MWCNT enhanced the flame retardance in both two composites and the limiting oxygen indices of randomly distributed structure and 3D segregated structure with 10 wt% MWCNT were 28.7% and 26.3%, respectively. The addition of MWCNT also improved the mechanical property in both two composites, while the improvement in randomly distributed structure was remarkedly larger than that in 3D segregated structure. Besides, the rheology results proved that the interaction between MWCNTs and CPE matrix in randomly distributed structure was stronger than that in 3D segregated structure. The results are beneficial to the manufacture of conductive polymer composites with appropriate electrical conductivities, balanced mechanical properties and flame retardant properties.