Expanded graphite ( EG ) as a potential filler in the reduction of percolation threshold of multiwall carbon nanotubes ( MWCNT ) in the PMMA/HDPE/EG/MWCNT nanocomposites

A facile route for the development of a conducting hybrid polymer nanocomposites composed of poly(methyl methacrylate) (PMMA)/high density polyethylene (HDPE) filled with multiwall carbon nanotube (MWCNT) and expanded graphite (EG) has been described. The EG used in this study was prepared by simple chemical exfoliation of graphite flakes and characterized by spectroscopic as well as morphological analysis. An industrially feasible melt mixing process was used for the preparation of the nanocomposites through sequential heating protocol. The judicious control of temperature during mixing revealed a highly co‐continuous structure of HDPE throughout the PMMA matrix and thus the percolation of the (75/25, w/w) PMMA/HDPE/bi‐filler nanocomposites was achieved at 0.07 wt% loading of MWCNT. An extensive analysis revealed that the selective dispersion of the conductive bi‐filler in the minor HDPE phase helped in the reduction of the percolation threshold through MWCNT–EG–MWCNT networking. The morphology, electrical conductivity, and their interrelation of the prepared nanocomposites can be found in detail in the manuscript. POLYM. COMPOS., 37:2070–2082, 2016. © 2015 Society of Plastics Engineers