Polythiophene–graphene oxide doped epoxy resin nanocomposites with enhanced electrical, mechanical and thermal properties

Abstract

In this paper hybrid fillers composed of polythiophene (PTh) nanoparticle decorated Graphene Oxide (GO), that was prepared via in situ chemical polymerization of the thiophene monomer in the presence of GO, were successfully dispersed into an epoxy matrix to serve as promising reinforcements. FTIR spectroscopy, X-ray diffraction, SEM and TEM analysis were used to confirm the formation of PTh–GOs hybrids and their dispersion within the epoxy matrix. The mechanical (Tensile Properties), electrical (AC and DC conductivity) and thermal stability of the epoxy nanocomposites were also investigated. A morphological study provided useful information for understanding the relationship between the dispersion of PTh–GOs and final properties of the epoxy composites. Because of the homogeneous dispersion of PTh–GOs in the epoxy matrix due to the strong interaction between functionalized groups on the GO surface and epoxy matrix, the nanocomposite presented obvious improvements in tensile properties with a small quantity (1.5 wt%) of the PTh–GO addition. Tensile strength and Young's modulus were increased 32% and 64%, respectively. The high aspect ratio of the PTh–GO enabled the formation of a conductive path way more easily than the PTh to provide a lower percolation threshold value. The real permittivity was observed to increase on increasing the PTh–GO nanofiller loading, and the enhanced permittivity was interpreted by the interfacial polarization. A reasonable improvement in the thermal stability of the epoxy nanocomposite was also observed. Thermal property observation using thermogravimetric analyses (TGA) demonstrated that the thermal stability of the nanocomposites is enhanced due to dispersion of PTh–GO in the matrix. We also compared the reinforcing effect of PTh–GOs with those of pure PTh and GO.