Barrier, mechanical and conductive properties of polycaprolactam nanocomposites containing carbon-based particles: Effect of the kind of particle

Abstract

In this study, polycaprolactam (PA6) nanocomposites with thermally reduced graphene oxide (TrGO) and carbon nanotubes (CNTs) were prepared by melt blending with the aim of obtaining films with improvements in permeability (oxygen and water vapor), mechanical properties and electrical conductivity. The permeability to water vapor and oxygen of the nanocomposites containing TrGO significantly decreased with increasing filler load due to a more tortuous path to gas permeation. For CNT nanocomposites, low barrier properties were found. The tensile tests showed similar behavior in both cases, with somewhat higher elastic modulus for TrGO compounds. CNT gave higher electrical conductivity to polyamide with lower percolation threshold; however this conductivity reached a constant value around 10 wt% of filler. The conductivity of TrGO nanocomposites was lower, probably due to the presence of impurities in its structure; however, the property increased up to 15 wt% of filler load without evidence of stabilization at this concentration.