Electrical conductivity of graphene filled PLA/PMMA blends: Experimental investigation and modeling

In order to gain a fundamental understanding about the influences of filler characteristic on the electrical properties of polymer blend nanocomposites two types of graphene, graphene nanoplates (GNPs) and functionalized graphene (FG), were added to immiscible blend of poly (lactic acid)/poly(methyl methacrylate) (PLA/PMMA) and experimental and theoretical studies were carried out. Structure and properties of graphenic nanoparticles were investigated by Raman spectroscopy, elemental analysis, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and X‐ray diffraction (XRD). The state of dispersion and distribution of fillers within the blend were examined by field emission scanning electron microscopy, Atomic force microscopy, transmission electron microscopy as well as XRD patterns. Theoretical modeling was carried out by several statistical and thermodynamic based models. Results showed that FG was more homogenously dispersed in the PLA matrix compared with GNP which results in lower percolation threshold and better electrical conductivity in the FG filled blends, despite its poor intrinsic electrical conductivity. For the PLA/PMMA blends filled composites, electrical conductivity modeling results showed that thermodynamic‐based models exhibit more satisfactory estimations than Power law statistical model. Thus, the electrical conductivity of two‐phase polymer blend filled with graphenic materials is predictable with thermodynamic models. POLYM. COMPOS., 40:704–715, 2019. © 2018 Society of Plastics Engineers