Investigation of anticorrosive properties of novel silane-functionalized polyamide/GO nanocomposite as steel coatings

Abstract Corrosion can cause many potential disasters including loss of life, negative social impacts, large portion of the total costs and water resource and environmental pollution, therefore, it is worth to be investigated in different applications. A hydroxyl containing aromatic polyamide was synthesized from condensation reaction of monomers 4,4ʹ oxydianiline and 5‑hydroxy isophathalic acid by ``Yamazaki'' method and was fully characterized. Then, this polyamide was modified with 3-chloropropyl trimethoxysilane with SN2 nucleophilic substitution reaction. Characterization of this modified polymer was also performed by 1HNMR and FT-IR spectroscopies. Finally, nanocomposites of modified polymer with graphene oxide (GO) were prepared. Thermal properties of the prepared polymer, modified polymer and related nanocomposites were evaluated by TGA and DSC analysis. The modified polymer and prepared nanocomposites were coated on steel substrate using casting solution. The corrosion resistance of prepared coatings was evaluated by electrochemical impedance spectroscopy (EIS) and Pull-off test. Results of EIS test indicated that adding GO to HPASi increased the corrosion resistance.