Enhancement the anticorrosive resistance of epoxy coatings by incorporation of CeO2 @ polyaniline @ 2-mercaptobenzotiazole nanocomposite

Abstract

Abstract To improve the corrosion protection properties of epoxy coatings, different weight percentages of CeO2/polyaniline/2-mercaptobenzothiazole nanocomposite with core-double shell structure (CeO2@PANI@MBT) were embedded in epoxy matrix. The CeO2@PANI@MBT organic/inorganic hybrid nanocomposite was successfully synthesized through layer by layer method during two steps. By the Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric analysis (TGA), Dynamic light scattering (DLS) and Zeta potential techniques, the formation of CeO2@PANI@MBT nanocomposite has been confirmed. The anticorrosive performance of CeO2@PANI@MBT nanocomposite into epoxy coating (EP/CeO2@PANI@MBT) was investigated using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), salt spray and pull off analysis. Compared to EP/CeO2 and pure EP, the as-prepared EP/CeO2@PANI@MBT coatings exhibited superior protective properties with high impedance modules (|Z|\u2009≥\u2009109) at low frequency (0.01\u2009Hz), minimum agglomeration and low permeability to water penetration. The highest coating resistance (Rcoat) was obtained in coating comprising of 1\u2009wt% CeO2@PANI@MBT (1.69\u2009×\u2009107\u2009Ω\u2009cm2), which had the lowest coating capacitance (1.30\u2009×\u200910−11\u2009Fcm−2). The water uptake of EP/CeO2@PANI@MBT 1\u2009wt% was 5.25 and 2.83 times lower than those considered for EP and EP/CeO2 coatings after 200\u2009h exposure to saline electrolyte at 65\u2009℃, respectively.