Synthesis and Characterization of Polypyrrole and Graphene/Polypyrrole/Epoxy Composites

Conducting polypyrrole (PPy) nanoparticles were synthesized via four different radical polymerization systems changing the time and other parameters. The characterization of PPy nanoparticles was done by Fourier transform infrared spectrometer. Graphene was synthesized from intercalated graphite by exfoliation at 1000 ∘ C for 30 s in tube furnace, and particle size was assessed using scanning electron microscope. Polypyrrole/graphene nano-composites were prepared by mixing PPy with graphene. Prior to this, graphene was coated with silane to enhance the bonding between PPy and graphene. The PPy-coated graphene composite was mixed in epoxy resin and cured using curing agent. The amount of PPy in nano-composites varied in the range of 1–20% by weight. The effect of PPy/graphene nanoparticles on mechanical and electrical properties and thermal stability of epoxy nano-composites was investigated. Thermal gravimetric analysis has shown that incorporation of PPy nanoparticles has improved the thermal stability of the epoxy nano-composites. Two probe electrical conductivity measurements have shown that increasing amount of graphene in PPy/epoxy nano-composites increases the conductivity of PPy significantly. In order to improve the dispersion of graphene in PPy, mechanical disperser was employed. Composites prepared with disperser have exhibited improvement in mechanical and thermal properties.