Synergistic Effect of Graphene Oxide and OH-MWCNTs on the Cure Kinetics of an Epoxy-Anhydride System

Dynamic differential scanning calorimetry (DSC) was used to investigate the synergistic effect of graphene oxides (GO) and hydroxyl functionalized multi-walled carbon nanotubes (OH-MWCNTs) on the cure behavior of a diglycidyl ether of bisphenol A (DGEBA) epoxy resin E-51 cured with methylhexahydrophthalic anhydride (MHHPA). The dynamic DSC results showed that with the introduction of nano-fillers, the initial reaction temperature, exothermal peak temperature, and finishing reaction temperature increased; while total heat of reaction decreased. The model-free Friedman method and model-fitting methods (Sestak-Berggren autocatalytic model and Kamal model) were employed to quantify the cure kinetics of the neat epoxy resin and nanocomposite respectively. The results indicate that the oxygenic functionalities on the surface of nano-fillers act as both a catalyst and initiator; and facilitated the early curing reaction. Moreover, the nano-fillers also facilitated the curing reaction at the diffusion-controlled stage due to their favorable thermal conductivity. Finally, the steric-hinerance effect of three-dimensional OH-MWCNTs caused a rise in the activation energy value.