Enhanced corrosion resistance and weathering resistance of waterborne epoxy coatings
A new study focuses 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-functionalized GO (DGO) were prepared on carbon steel surfaces.
Enhancing the weathering resistance
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 electrolytes for 0.2 wt% DGO-reinforced waterborne epoxy coatings, while that of the neat epoxy coatings dropped below 1 × 107 Ω after 10 days. Besides, the addition of DGO enhanced the weathering resistance of waterborne epoxy coatings.
After 60 days of the UV aging test, the yellow color index of neat epoxy coatings was 1.6 times that of 0.5 wt% DGO/epoxy coatings. The residual pencil hardness of the 0.5 wt% DGO/epoxy coatings was three levels higher than that of neat epoxy coatings.
The study has been published in Journal of Coatings Technology and Research volume 17 (2020).
