The mechanical behavior of modified epoxy adhesive using GNPs, MWCNTs, and RGO nanomaterials.

In this research, a comprehensive comparison of the effects of adding nanomaterials on mechanical behavior of structural adhesive was experimentally investigated. The nanomaterials, namely graphene nanoplatelets (GNPs), Multi-Walled Carbon Nanotubes (MWCNTs), and reduced graphene oxide (RGO) were introduced at varying weight fractions of 0.25, 0.5, 0.75, and 1 wt% within the host adhesive. In addition to the parameters of type of nanomaterial and weight fraction, the effect of nanomaterial functionalization was also included. Two types of primary functionalization: carboxyl (COOH) and amine (NH2) along with non-functionalized filler was utilized. The nanomaterials were mixed in a high viscous structural adhesive araldite® 2011 by following a comprehensive mixing method. Flat doge bone specimens were prepared according to ASTM standard and subjected to testing using a universal testing machine (UTM). The results of the experimentation showed that the mechanical behavior of epoxy adhesive is significantly influenced by the addition of any type carbonaceous nanomaterial (GNPs, MWCNTs, and RGO) in the study, however, significant variation in mechanical properties (Elastic Modulus, Tensile Strength, Failure Strain, and Tensile Toughness), as well as their respective trends was observed among these nanomaterials. Overall, the introduction of GNPs was observed to increase the brittleness of the epoxy adhesive, whereas MWCNTs exhibited a contrasting effect by reducing brittleness. Moreover, it was found that the effect of functionalization and filler concentration on resulting properties was independent of each other. [ABSTRACT FROM AUTHOR]