Anti-corrosive properties of vermiculite-enhanced waterborne epoxy resins with two-dimensional exfoliation

Abstract

Although waterborne epoxy resin coatings are widely used in the field of anti-corrosion, micropores and micro defects in their coatings are the key factors restricting their further development. The exfoliated vermiculite was stripped by a physical one-step stripping method, with good water dispersion and dense lamellar structure. As the nano-filler, it can effectively fill the micro defects in the coating, make the coating structure more compact, and effectively prevent the intrusion of corrosive media. When exfoliated vermiculite was added at 1%, two orders of magnitude increased the electrochemical impedance modulus to 2.276×106 Ω cm2 and the corrosion current was correspondingly reduced to 1.186×10−8 A cm−2, showing excellent corrosion resistance. Adding 1% exfoliated vermiculite creates a “labyrinth effect” in the coating that extends the penetration path of the corrosion particles, thus effectively preventing corrosion of the underlying metal substrate. This enables the coating to better cope with harsh corrosive environments and provides a viable idea for coating protection.