Synergistically enhancing the performance of cardanol-rich epoxy anticorrosive coatings using cardanol-based reactive diluent and its functionalized graphene oxide

In this paper, a new anti-corrosion composite coating with high-volume fraction of cardanol-based components was prepared using epoxy, cardanol-based reactive diluent (602A), and 602A functionalized graphene oxide nanosheets (A-GO). A one-step, low-cost method was adopted to synthesize the A-GO. By synergistically enhancing the matrix compactness, filler dispersibility, and matrix hydrophobicity, the cardanol-rich epoxy composite coating (A-GO/602A/epoxy) shows high anti-corrosion performance in the long term. The morphology and structure analyses show that the A-GO/602A/epoxy composite coating has i. enhanced matrix compactness, ii. optimized filler dispersibility and filler/matrix bonding strength, and iii. improved matrix hy-drophobicity. The electrochemical impedance spectroscopy (EIS) test was used to determine the anti-corrosion performance of the A-GO/602A/epoxy composite coating. After immersing in diluent NaCl solution (3.5 wt%) for 90 days, the increase of the impedance modulus of the A-GO/602A/epoxy composite coating maintains three orders of magnitude at low frequencies (0.01 Hz) compared to the pure petroleum-based epoxy coating, indi-cating that the corrosion properties of the composite coating can be significantly enhanced by synergistically optimization of the three factors. Our results show the high potential of cardanol-rich epoxy coatings in the field of anti-corrosion epoxy coatings, and may give a guide to the design of high-performance anti-corrosion epoxy coatings.

Automated summary

In this study, a new anti-corrosion composite coating was prepared with high anti-corrosion performance achieved by enhancing matrix compactness, filler dispersibility, and matrix hydrophobicity synergistically.