Mechanical Characterization of Polymer Nanocomposites Reinforced with Graphene Nanoplatelets

Abstract

Fiber reinforced polymer (FRP) composites have been extensively used for strengthening concrete structures. To manufacture FRPs or bond them to concrete structures, usually thermoset polymers are used. The mechanical properties and integrity of these adhesives significantly affect the performance of FRP-strengthened structures. Graphene nanoplatelets (GNPs) are carbon-based functional fillers that possess large surface area and high aspect ratio. They are easy to be processed in the host matrix and have excellent material properties at a relatively low cost. This study investigates the tensile behavior of GNP-reinforced nanocomposites. Two different epoxy matrices, one ductile and another brittle, are considered. First, the effect of ultrasonication duration in dispersion of GNPs is studied. Then, specimens with different GNP concentration levels are prepared to assess the effect of GNP content on the developed nanocomposites. Monotonic uniaxial tensile tests are conducted to study the effect of GNP addition to tensile strength and tensile modulus of two different epoxy resins. Morphology of GNPs and the fracture surface of the developed nanocomposites are also observed using SEM to assess the dispersion of GNPs. Results shows that both tensile strength and tensile modulus of ductile epoxy increase with increasing GNP content up to 1 wt. %, while for brittle epoxy a significant increase in tensile modulus is observed with 2 wt. % GNP concentration together with a slight decrease in tensile strength.