Green construction of melamine phytate nanosheets for enhancing anti-corrosive performance of water-borne epoxy coatings

Two-dimensional (2D) materials have a comprehensive application in anti-corrosion coatings as nano-packing due to their large diameter/thickness ratio and wonderful barrier performance for water and oxygen. However, some disadvantages restrict the introduction of 2D materials into polymer matrix, including complicated preparation and modification processes, high costs, etc. In this study, an environment-friendly melamine phytate (PM) nanosheets were prepared and then introduced into the polymer matrix without any modification for fabricating water-borne epoxy (WEP) composite coatings. Long-term electrochemical test shows that 1.0 wt% PM/WEP exhibits the best anti-corrosion performance: highest log |Z| at 0.01 Hz value (7.8 Ω cm2) and lowest Icorr (2.83 × 10–9 A cm−2), and the minimum corrosive iron content in corrosion products after film remove (the oxygen and chlorine contents are 4.66% and 0.05%, respectively). These results reveal that proper addition of PM nanosheets could extremely improve the anti-corrosion performance in composite coatings. This research provides a mentality for the large-scale application of 2D materials into polymer coatings.Graphical abstractPM nanosheets were prepared by hydrothermal process which using melamine (MA) and phytic acid (PA), two green and eco-friendly raw materials. And then the nanosheets were firstly introduced into water-borne epoxy resin (WEP). On the lower right, it is a scanning electronic image (SEM) of PM nanosheets. To the lower left, it is the corrosion protection between blank WEP, 0.5 wt% PM/WEP, 1.0 wt% PM/WEP and 1.5 wt% PM/WEP coatings.