PEDOT-hydroxypropyl-β-cyclodextrin Inclusion Complex as Additive for Epoxy Coating with Enhanced Anticorrosion Performance

Abstract

PEDOT is a conductive polymer with a conjugated structure, which has great steric hindrance and ion exchange capacity, but its compatibility is poor. Herein, a novel PEDOT-hydroxypropyl-β-cyclodextrin (P-CD) inclusion complex was synthesized and was used as an additive for anticorrosive epoxy coating. UV, FTIR, Raman and XRD spectra demonstrated that the HP-β-CD was successfully attached with the PEDOT and enhanced the solubility and dispersion of PEDOT. The epoxy coatings without and with a small content of P-CD (0.5 wt.%, 1 wt.%) were prepared and the anticorrosion properties were assessed by electrochemical impedance spectroscopy (EIS) and corrosion product analysis. The results indicate that the composite coating exhibits a higher impedance modulus compared to the pure epoxy coating. The main reason is the barrier performance of P-CD, which increases the diffusion path of corrosive media, and P-CD can enhance corrosion resistance by promoting the formation of Fe3O4 passivation layer on the surface of steel.