This new study focused on the enhanced corrosion resistance and weathering resistance of waterborne epoxy coatings with polyetheramine-functionalised graphene oxide. Polyetheramine (D230), an epoxy curing agent, was grafted on graphene oxide (GO) surfaces, which can be stably dispersed in a waterborne curing agent for more than 8 months. Waterborne epoxy coatings reinforced by D230-functionalised GO (DGO) were applied on carbon steel surfaces.
According to the electrochemical impedance spectra, the impedance modulus at 0.1 Hz remained at 2.2 × 109 Ω after 150 days of immersion in 3.5% NaCl with a 0.2 wt% DGO-reinforced waterborne epoxy coatings, whilst that of the neat epoxy coating dropped below 1 × 107 Ω after 10 days. In addition, the addition of DGO was found to enhance the weathering resistance of waterborne epoxy coatings. After 60 days of the UV aging test, the yellow colour index of a neat epoxy coating was 1.6 times that of a 0.5 wt% DGO/epoxy coating. The residual pencil hardness of the 0.5 wt% DGO/epoxy coating was three levels higher than that of neat epoxy coating.
The study was published in the Journal of Coatings Technology and Research, Volume 17 (2020).