Study On The Multi-component Conductive Polymer Composites Filled With Carbon Fibers

It is important to remain or improve the conductivity and electrical stability of conductive polymer composites, while reducing the content of the conducitve fillers to optimizing the processability. The electrical behavior and electrical stability of multi-component polymer composites filled with carbon fibers are studied in this paper.Firstly, poly (methyl methacrylate) (PMMA) and high density polyethylene (HDPE) blend was selected as the polymer matrix in this paper. And the blend of carbon nano-fiber (CNF)/carbon black (CB) and the blend of vapor grown carbon fiber (VGCF)/Ketjen black (KB) were selected as the conductive fillers. The quaternary conductive composites of PMMA/HDPE/CB/CNF and PMMA/HDPE/KB/VGCF were prepared. In the both composites, the content of PMMA was much more than that of HDPE.In PMMA/HDPE/CB/CNF composites, the scanning electron microscopy (SEM) photographs showed that the CB and CNF were selectively distributed in the HDPE phase and formed unique microcosmic structure of networks. Compared with PMMA/fillers and PMMA/HDPE/fillers, the PMMA/HDPE/CB/CNF composites got the less percolation threshold and better conductivity than other systems. CNF and CB particles revealed synergistic effect in the PMMA/HDPE/CB/CNF composites. Compared with other systems, the positive temperature coefficient effect (PTC) intensity was promoted and the negative temperature coefficient effect (NTC) was reduced in this system.In PMMA/HDPE/KB/VGCF conductive composites, KB particles were selectively distributed in the dispersed phase (HDPE phase) and VGCFs contacted with eachother. Conductive fillers self-assembly formed micro electric network structure like scaffolding by thermodynamics. Compared with other systems, the PMMA/HDPE/KB/VGCF composites got the lowest percolation threshold (only 1.3 wt %). KB particles and VGCF also revealed synergistic effect in the PMMA/HDPE/KB/VGCF composites. Secondly, ternary conductive composite composites of low density polyethylene (LDPE)/carbon fiber (CF)/polyaniline (PANI) with dodecylbenzenesulfonic acid (DBSA) were also pepared in this paper. The influence of the addition of DBSA on the micro-morphologies of conductive polymer composites was studied. The room-temperature resistivity and stability of composites were also discussed.