Abstract
The methods for the design of highly corrosion resistance nanocomposite on the surface of steel with oxide layers have been described. Self-stabilized magnetic polymeric nanoparticles of coated sodium 2-acrylamido-2-methyl propane sulfonate-co-N-Isopropyl Acrylamide/magnetite, NIPAAm/AMPS-Na/Fe3O4, was prepared by surfactant-free radical polymerization using N, N-methylenebisacrylamide (MBA) as crosslinker, and potassium persulfate (KPS) as an initiator in the presence of hydrophilic poly(vinyl pyrrolidone) coated magnetite particles. The chemical structures of the modified NIPAAm/AMPS-Na/Fe3O4 were confirmed by FTIR analysis. The morphology and the particle size distributions of the NIPAAm/AMPS-Na/Fe3O4 composite were observed and analyzed by transmission electron microscopy (TEM). The average Fe3O4 content of NIPAAm/AMPS-Na/Fe3O4 was determined by thermogravimetric analysis (TGA). The inhibitive action of NIPAAm/AMPS-Na/magnetite nanogel on corrosion of steel in 1 M HCl solution was investigated through polarization and electrochemical impedance spectroscopy (EIS). The increase in inhibition efficiency with inhibitor concentration is associated with a shift of both cathodic and anodic branches of the polarization curves towards lower current densities and suggested that NIPAAm/AMPS-Na/magnetite nanogel acted as mixed type inhibitor. The results indicate good agreement between the values of inhibition efficiency (IE%) as obtained from the impedance technique and polarization measurements.