Improved dielectric and dynamic mechanical properties of epoxy/polyaniline nanorod/in situ reduced graphene oxide hybrid nanocomposites

The incorporation of hybrid fillers such as conducting polymer/graphene in polymer matrices affords promising materials with high dielectric constant suitable for electronic devices. Initially PANI/GO hybrid was prepared via in situ oxidative polymerization of aniline on GO. The hybrid was dispersed in dichlorobenzene and then incorporated in epoxy resin. The evaporation of the solvent resulted in in situ reduction of GO and the mixture was cured. The effect of PANI/rGO hybrid filler on the morphology, electrical conductivity, dielectric, dynamic mechanical, and thermal properties of epoxy nanocomposites was evaluated. The electrical conductivity of the nanocomposite containing 9 wt% of the filler (EPG9) enhanced by five orders of magnitude compared to neat epoxy, that is, from 5.6 x 10(-13) to 1.27 x 10(-8) S/cm. A high dielectric constant (epsilon ') of 208 was achieved for EPG9. The dielectric loss tangent (tan delta) was low for the hybrid nanocomposites at 10(3) Hz. DMA studies revealed that the storage modulus (E ') increased significantly with the incorporation of hybrid fillers. The tensile strength and Young's modulus of the EPG3 nanocomposites improved by 14.3% and 33.1%, respectively compared to neat epoxy. SEM and TEM studies revealed the uniform dispersion of the hybrid filler at 3 wt% in the epoxy matrix. The addition of PANI/rGO filler also improved the thermal stability of the epoxy nanocomposites.