Heat tolerant epoxy-amine functionalized graphene oxide composites for insulation applications

Abstract

Heat tolerant polymers are in much demand in electrical, structural, and electronic packaging applications. This article reports on a comparison of epoxy composites reinforced with graphene oxide (GO) and amine-functionalized GO (AGO) on their dielectric properties and adhesive strength in the temperature range of 30–110 °C. GO was synthesized using the modified Hummers method and functionalized with amine functional group using hexamethylenediamine (HMDA) and confirmed by Raman spectroscopy. Various filler concentrations (0.2–0.6 wt.%) of GO/AGO epoxy nanocomposites were prepared using the solution blending method and analyzed using a dynamic mechanical analyzer (DMA), impedance spectroscopy, and the single lap shear (SLS) test. Studies showed AGO reinforced epoxy composites outperforming than neat epoxy and GO-epoxy composites for all the compositions. The optimum concentration of AGO was found to be 0.4 wt.% based on its relative permittivity, dielectric loss and retention of adhesive strength up to 90 °C. The percentage of cohesive area on the fractured surface of SLS tested AGO was ∼1.4 and ∼3 times better than that of GO-epoxy and neat epoxy, respectively. The higher strength retention of AGO-epoxy nanocomposites is suitable for high-temperature insulation applications as adhesive coatings.