Curing of graphene-epoxy nanocomposites: influence of cross-linking / resin ratio

Abstract

In the present work the influence of the graphene type (GNP) and the different crosslinking agent ratios in the curing of graphene-epoxy dispersions and in the glass transition temperature (Tg) of the formed nanocomposite is studied. The epoxy resin type DGEBA (LY) has been crosslinked with an aromatic polyamine (XB). Two types of graphene have been used: one non-functionalized (GNPn) and another functionalized with amino groups  (GNPNH2). In the two systems, 5 compositions with different XB / LY ratios have been studied and, the content of graphene has been varied (6 and 10% by weight). The curing reaction has been studied by Differential Scanning Calorimetry. It has been observed that the presence of graphene accelerates the curing reaction and that the enthalpy of reaction depends on stoichiometry and graphene content. It has also been found that the variation of the Tg of the material with the stoichiometry, depends on the curing protocol.

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