Effect of carbon nanotubes on the corrosion resistance of water-borne acrylic coatings

The effects of multiwalled carbon nanotubes (MWCNTs) on the adhesion strength and corrosion resistance of the acrylic nanocomposite coatings were evaluated on Q235 substrates via pull-off tests and electrochemistry measurements (EIS, LEIS). Addition of MWCNTs to the acrylic resulted in an up to ∼50% increase in the adhesion strength. After 36 h of immersion in 3.5 wt% NaCl, the coating resistance of the native acrylic coating was 235.8 Ω cm2, whereas those of the nanocomposite coatings containing 0.5 and 1 wt% MWCNTs were 1.36 × 105 and 9.27 × 107 Ω cm2, respectively. LEIS analysis indicated that the addition of MWCNTs increased the adhesion strength and retarded the delamination. The results demonstrated the positive effects of the incorporation of MWCNTs on the anticorrosive ability of the coatings.