Pursuit of electroconducting thermoplastic vulcanizates: activated charcoal-filled polypropylene/ethylene–propylene–diene monomer blends with upgraded electrical, mechanical and thermal properties

Abstract

Conducting polymer blends are getting attention due to their demanding applications in static charge dissipation processes. In the current study, polypropylene (PP)– and ethylene–propylene–diene monomer-based nanocomposites, filled with varying loadings of intrinsically conducting activated charcoal (AC) nanoparticles, were blended in the presence of methyl methacrylate (MMA)-based compatibilizer and sulfur-based vulcanization system to prepare electroconducting thermoplastic vulcanizates (TPVs). Fourier-transform infrared spectroscopy, confirming successful grafting of MMA on PP chains, was employed to perform structural analysis of the samples. Relative distribution of filler in polymer and rubber phases, level of homogeneity of filler distribution and optimum state of filler dispersion were analyzed via scanning electron microscopy. Improved degree of crystallinity, thermal stability and other characteristic temperatures of the prepared specimens were determined via differential scanning calorimetry and thermogravimetric analysis. Increasing filler contents considerably improved tensile strength, stiffness, and hardness of the prepared TPVs. Doping of AC into electrically insulator TPVs turned them into almost a semiconducting material as indicated by significant enhancement in their electrical conductivity values.