Synergistic effect of multiwalled carbon nanotubes and carbon black on rheological behaviors and electrical conductivity of hybrid polypropylene nanocomposites

Abstract

The monograph, electrical conductivity, and rheological behaviors of isotactic polypropylene /carbon black (CB)/multiwalled carbon nanotubes (MWCNTs) composites were studied. Ternary composites including MWCNTs and CB revealed an electrical property similar to the binary MWCNTs composites. This work showed that a synergistic effect result in preserved electrical behavior with a simultaneous effective reduced of the MWCNTs amount. Moreover, the combination of conductive fillers also resulted in a decreased rheological percolation threshold, an accelerated formation of rheological network and a delay in the destruction of the filler network. The similar value of the activation energy for CB/MWCNTs and MWCNTs verified the existence of a co‐supporting networked formed by MWCNTs and CB. Two strain‐softening processes are found in a strain sweep for the ternary composite melt with high filler loading. The low‐strain‐softening process may be an indication that the MWCNTs filler network is broken into separated aggregated structures, while the high‐strain‐softening process should be related to the breakdown of the temporary network structure. POLYM. COMPOS., 39:E723–E732, 2018. © 2016 Society of Plastics Engineers