Effect of water absorption on dielectric constant of TMD cured of carbonaceous filled epoxy composites

Abstract

Carbon nanotubes (CNT) and graphene nanoparticles (GNP) have been used as carbonaceous filler in epoxy composites based on the diglycidyl ether of bisphenol A (DGEBA) cured with tetra methyl diamine (TMD). Both CNT/epoxy and GNP/epoxy nanocomposites were subjected to ageing at 0%, 30%, 50%, 70% and 100% of relative humidity at room temperature for three weeks. Both composites show increasing water absorption percentage at higher relative humidity. Moreover, the GNP/epoxy nanocomposites showed a higher water absorption compared to CNT/epoxy nanocomposites. The dielectric constant increment of both nanocomposites is parallel to the water absorption properties. It is concluded that water absorption leads both to increase the dielectric constant of the epoxy resin.