Polypyrrole/graphene nanosheets/rare earth ions/dodecyl benzene sulfonic acid nanocomposite as a highly effective anticorrosive coating

Organic-inorganic nanocomposites (PPy/GNS/RE3+/DBSA) involving pyrrole (Py), graphene nano sheets (GNS), rare earth elements (RE3+ = La3+, Sm3+, Nd3+) and dodecyl benzene sulfonic acid (DBSA) were synthesized via in situ chemical oxidative polymerization using FeCl3 as an oxidant. PPy/GNS/DBSA and PPy/DBSA was also synthesized by following the identical synthesis route. The resultant nanocomposites were characterized by FTIR, XRD, SEM and TEM. The synthesized nanocomposites were chemically deposited on low carbon steel specimens by solvent evaporation method using N-Methyl-2-pyrrolidone (NMP) as solvent and 10% epoxy resin (by weight) as binder. The anticorrosive nature of polymer coatings were studied in 0.1 M HCl solution by subjecting them to various corrosion tests, which includes: EIS, potentiodynamic polarization, free corrosion potential (OCP) measurement and immersion test. The surface morphology of coated samples before and after immersion was evaluated using SEM. (C) 2016 Elsevier B.V. All rights reserved.