Epoxy/PAMAM dendrimer-modified graphene oxide nanocomposite coatings: Nonisothermal cure kinetics study

Highly curable nanocomposite coatings based on epoxy, graphene oxide (GO), and amine -terminated poly-amidoamine (PAMAM) dendrimer-modified GO (GO-PAMAM) are prepared and their cure behavior and kinetics are discussed. The surface of the GO platelets is chemically functionalized by PAMAM and characterized by Fourier transform infrared spectroscopy and thermogravimetric analyses. Nonisothermal cure kinetics of the prepared nanocomposite coatings are studied by the aid of differential scanning calorimetry (DSC). The results of differential and integral isoconversional approaches are coincidently indicating a lower activation energy for the epoxy/GO-PAMAM nanocomposite coatings over the whole range of conversion, particularly at later cure stages where crosslinking is agreed to be mainly controlled by the diffusion, with respect to the samples containing pristine GO. The facilitated crosslinking in epoxy nanocomposites containing GO-PAMAM has been discussed on the bedrock of autocatalytic and noncatalytic nature of the monitored cure kinetics using mathematical models.