Effect of the cross-linker content and type of graphene on the thermo-mechanical properties of nanocomposites

Abstract

In this paper we study the influence of the type of graphene (GNP) and the different ratios of the crosslinking agent (XB)-resin epoxy (LY) on the thermo-mechanical properties of epoxy-graphene nanocomposites (GNP). Epoxy/GNP nanocomposites have been prepared using two different types of graphene: one non-functionalized (GNPn) and one amino functionalized graphene (GNPNH2). The content of graphene has been 6% and 10% by weight. The thermo-mechanical properties of the LY-XB thermoset and the nanocomposites have been determined through dynamic mechanical thermal analysis and tensile tests in a universal testing machine. The glass transition temperature and the storage modulus in the elastomeric zone (T>Tg) of the thermoset LY-XB and the nanocomposites have maximum values ​​for slightly rich amine content. The addition of graphene significantly increases the elastic modulus of the nanocomposites compared to the neat epoxy thermoset (LY-XB), both in the vitreous region (T<Tg) and in the elastomeric region (T>Tg). The thermoset LY-XB shows the best strength and toughness for the stoichiometric ratio XB/LY. The addition of graphene leads to more rigid but more fragile materials.