Combined Thermomechanical Effect of Graphene Oxide and Montmorillonite on Biobased Epoxy Network Formation for Coatings

Abstract

Epoxy nanocomposites derived from linseed oil, reinforced with graphene oxide (GO) and montmorillonite (MMT) nanostructures, were synthesized. The nanohybrids were developed by enriching the structure of MMT and GO with primary amines through a common and simplified method, which implies physical interactions promoted by ultrasonic processing energy. The influence of the new nanoreinforcing agents along with neat ones on the overall properties of the biobased epoxy materials for coating applications was assessed. Interface formation through surface compatibility was contained by the lower values of activation energy calculated from differential scanning calorimetry (DSC) curves, along with a consistent 70% increase in the cross-linking density when aminemodified MMT was used. Thermomechanical characteristics of the biobased epoxy nanocomposites were explained through the interaction of the functional groups over the curing process of epoxidized linseed oil (ELO), giving a 15 °C higher T g value increase. Furthermore, the low surface energy values suggested an intrinsic antibacterial activity, as proved by a significant decrease of CFU against Staphylococcus aureus bacterial strains on the 0.25% reinforced coatings.