High Strength Epoxy Composite Coating Based on Polyaniline‐Modified Montmorillonite Nanosheets for Synergistic Corrosion Protection

Abstract

ABSTRACT Anticorrosion coatings are the primary measure for metal protection. Traditional epoxy (EP) resin anticorrosion coatings fail to provide metal protection due to defects that allow corrosive media to penetrate. Adding nanofillers that can block and consume corrosive media is an essential means of enhancing the corrosion‐resistant performance of EP coatings. Montmorillonite (MMT) nanosheets possess excellent barrier properties and mechanical performance, while polyaniline (PANI) and phytic acid (PA) have excellent passivation and corrosion inhibition properties. In this work, phytic‐doped polyaniline encapsulated MMT nanomaterials (PANI/MMT) are prepared as fillers for EP resins, improving the strength and corrosion resistance of the coatings. Due to the rough surface of PANI/MMT nanosheets and their excellent compatibility with EP resin, they can fill defects in the coating, enhancing its strength (3.09 MPa, compared to 1.5 MPa for pure EP). The | Z | 0.01 Hz of the PANI/MMT/EP coating after being immersed in a 3.5 wt% NaCl solution for 150 days is 6.75 × 10 8 Ω cm 2 . This is three orders of magnitude higher than that of the EP coating alone. Based on these findings, PANI/MMT holds significant potential for the development of long‐term corrosion‐resistant coatings.