Thermal properties and curing kinetics of epoxy powder coatings containing graphene nanoplatelets

Graphene nanoplatelets (GNP) have excellent properties, such as high mechanical strength and good thermal conductivity, making them interesting nanofiller for their application in powder coatings. In this context, the aim of this study was to evaluate the thermal behavior and the curing kinetics of epoxy powder coatings containing GNP. The coatings were obtained by mixing in a ball mill followed by homogenization in molten state. The GNP were dispersed directly into the epoxy powder. The morphology, thermal stability and curing kinetics of the samples were evaluated. During the curing process, the GNP accelerated the onset of the reaction but ultimately caused steric impediment. From the results, the GNP incorporated to the solid epoxy resin for coatings behaved differently in each stage of the curing process. In general, while the direct dispersion of GNP in powder epoxy by dry mixing methods was not ideal, the thermal properties were improved, with GNP inducing a poor curing state where diffusion phenomena are predominant.