1Nanotechnology and Carbon Research Group, Faculty of Downstream Petroleum Industry, Research Institute of Petroleum Industry (RIPI), Tehran, Iran
2Coating Research Group, Industrial Protection Research Division, Research Institute of Petroleum Industry, N.I.O.C., Tehran, Iran
The corrosion protection of mild steel by a newly developed epoxy-based coating system containing inherently conducting nanopolyaniline-clay as a nanoadditive has been studied. Polyaniline-clay anticorrosion nanoadditive (PCNA) was obtained by the direct mixing method of nanopolyaniline (0.03 wt.%) and organo-modified clay (3 wt.%) at atmospheric pressure, and XRD technique was used to study d-spacing of clay platelets in the prepared nanoadditive. PCNA was dispersed in polyaminoamide hardener matrix and was used for epoxy coating (EPCNA) preparation. The particle size of the polyaniline in hardener was determined using dynamic light scattering technique (DLS). The results revealed that the particles were in the range of 50–58 nm. The degree of exfoliation and distribution and particles size were studied by XRD and TEM in the final dried film. The corrosion protection ability of EPCNA was compared to an epoxy coating containing pure nanopolyaniline (ENPN) using electrochemical impedance spectroscopy (EIS) and salt spray methods. In addition, an investigation on the morphology of metal-coating interface by scanning electron microscopy (SEM) technique in ENPN and EPCNA samples after salt spray test showed stable oxide layer formation for ENPN and a dense stable oxide layer for EPCNA on metal surface. The results showed that the PCNA nanoadditive enhanced corrosion protection effect in comparison to pure nanopolyaniline (NPN) in the epoxy coating.
Bhupesh M. and Abhishek K., “Nano additives: A Review,” Paintindia, 2008, 58, 113-132.
Sawitowski T., “Nano and Hybrid Coatings Conference,” Manchester, UK, 2005.
Yeh J. M. and Chang K. C., “Polymer/layered Silicate Nanocomposite Anticorrosive Coatings,” J. Ind. Eng. Chem., 2008, 14, 275-291.
Bagherzadeh M. R. and Mahdavi F., “Preparation of Epoxy–clay Nanocomposite and Investigation on its Anti-corrosive Behavior in Epoxy Coating,” Prog. Org. Coat., 2007, 60, 117–120.
Bagherzadeh M. R., Ghasemi M., Mahdavi F., and Shariatpanahi H., “Investigation on Anticorrosion Performance of Nano and Micro Polyaniline in New Water-based Epoxy Coating,” Prog. Org. Coat., 2011, 72, 348–352.
Bagherzadeha M. R., Mahdavi F., Ghasemi M., Shariatpanahi H., et al., “Using Nano-emeraldine Salt-polyaniline for Preparation of a New Anticorrosive Water-based Epoxy Coating,” Prog. Org. Coat., 2010, 68, 319-322.
Chen F. and Liu P., “Conducting Polyaniline Nanoparticles and their Dispersion for Waterborne Corrosion Protection Coatings,” Appl. Mater. Interfaces, 2011, 3, 2694-2702.
 Khan M. I., Chaudhry A. U., Hashim S., Zahoor M. K., et al., “Recent Developments in Conductive Polymer Coatings for Corrosion Protection,” Chem. Eng. Res. Bull., 2010, 14, 73-86.
Pavlidou S. and Papaspyrides C. D., “A Review on Polymer–layered Silicate Nanocomposites,” Prog. Polym. Sci., 2008, 33, 1119-1198.
Akbarinezhad E., Ebrahimi M., and Sharif F., “Synthesis of Exfoliated Polyaniline-clay Nanocomposite in Supercritical CO2,” J. Supercrit. Fluid, 2011, 59, 124-130.
Olad A. and Rashidzadeh A., “Reparation and Anticorrosive Properties of PANI/Na-MMT and PANI/O-MMT Nanocomposites,” Prog. Org. Coat., 2008, 62, 293–298.
Kataria D., “Polyaniline Clay-polyimide Hybrid Nanocomposite Coatings for Corrosion Protection of AA 2024,” M.S. Thesis, University of Cincinnati, USA, 2005.
Chen Y., Wang X. H., Li J., Lu J. L., et al., “Polyaniline for Corrosion Prevention of Mild Steel Coupled with Copper,” Electrochim. Acta., 2007, 52, 5392-5399.
Yeh J. M., Liou S. J., Lai C. Y., Wu P. C., et al., “Enhancement of Corrosion Protection Effect in Polyaniline via the Formation of Polyaniline-clay Nanocomposite Materials,” Chem. Mater., 2001, 13, 1131-1136.
Song D. H., Lee H. M., Lee K. H., and Choi H. J., “Intercalated Conducting Polyaniline-clay Nanocomposites and their Electrical Characteristics,” J. Phys. Chem. Solids, 2008, 69, 1383-1385.
Sudha J. D. and Sasikala T. S., “Studies on the Formation of Self-assembled Nano/microstructured Polyaniline–clay Nanocomposite (PANICN) using 3-Pentadecyl Phenyl Phosphoric Acid (PDPPA) as a Novel Intercalating Agent Cum Dopant,” Polymer, 2007, 48, 338-347.
Yoshimoto S., Ohashi F., Ohnishi Y., and Nonami T., “Synthesis of Polyaniline-montmorillonite Nanocomposites by the Mechanochemical Intercalation Method,” Synthetic Met., 2004, 145, 265-270.
Soto-Oviedo M. A., Ara´ujo O. A., Faez R., Mirabel C., et al., “Antistatic Coating and Electromagnetic Shielding Properties of a Hybrid Material Based on Polyaniline/organoclay Nanocomposite and EPDM Rubber,” Synthetic Met., 2006, 156, 1249-1255.
Jang J., Bae J., and Lee K., “Synthesis and Characterization of Polyaniline Nanorods as Curing agent and Nanofiller for Epoxy Matrix Composite,” Polymer, 2005, 46, 3677-3684.
Bhadra S., Khastgir D., Singha N. K., and Lee J. H., “Progress in Preparation, Processing and Application of Polyaniline,” Prog. Polym. Sci., 2009, 34, 783-810.
Hoang H. V. and Holze R., “Electrochemical Synthesis of Polyaniline/Montmorillonite Nanocomposites and their Characterization,” Chem. Mater., 2006, 18, 1976-1980.
Hosseini M. G., Raghibi-Boroujeni M., Ahadzadeh I., Najjar R., et al., “Effect of Polypyrrole-montmorillonite Nanocomposites Powder Addition on Corrosion Performance of Epoxy Coatings on Al 5000,” Prog. Org. Coat., 2009, 66, 321-327.
Kiliaris P. and Papaspyrides C. D., “Polymer/layered Silicate (Clay) Nano-composites: An Overview of Flame Retardancy,” Prog. Polym. Sci., 2010, 35, 902-958.
 Twite R. L. and Bierwagen G. P., “Review of Alternatives to Chromate for Corrosion Protection of Aluminum Aerospace Alloys,” Prog. Org. Coat., 1998, 33, 91-100.
Kinlen P. J., Silverman D. C., and Jeffreys C. R., “Corrosion Protection using Polyaniline Coating Formulations,” Synth. Met., 1997, 85, 1327-1332.
Saravanan K., Sathiyanarayanan S., Muralidharan S., Syed Azim S., et al., “Performance Evaluation of Polyaniline Pigmented Epoxy Coating for Corrosion Protection of Steel in Concrete Environ-ment,” Prog. Org. Coat., 2007, 59, 160-167.
Podsiadlo P., Shim B. S., and Kotov N. A., “Polymer/clay and Polymer/carbon Nanotube Hybrid Organic-inorganic Multilayered Composites made by Sequential Layering of Nanometer Scale Films,” Coordin. Chem. Rev., 2009, 253, 2835-2851.
 Armelin E., Pla R., Liesa F., Ramis X., et al., “Corrosion Protection with Polyaniline and Polypyrrole as Anticorrosive additives for Epoxy Paint,” Corros. Sci., 2008, 50, 721-728.
Akbarinezhada E., Ebrahimi M., Sharif F., Attar M. M., et al., “Synthesis and Evaluating Corrosion Protection Effects of Emeraldine Base PAni/clay Nanocomposite as a Barrier Pigment in Zinc-rich Ethyl Silicate Primer,” Prog. Org. Coat., 2011, 70, 39-44.
Saravanan K., Sathiyanarayanan S., Muralidharan S., Syed Azim S., et al., “Performance Evaluation of Polyaniline Pigmented Epoxy Coating for Corrosion Protection of Steel in Concrete Environment,” Prog. Org. Coat., 2007, 59, 160-167.
Sathiyanarayanan S., Muthukrishnan S., and Venkatachari G., “Performance of Polyaniline Pigmented Vinyl Acrylic Coating on Steel in Aqueous Solutions,” Prog. Org. Coat., 2006, 55, 5-10.
Castela A. S. L., Simoes A. M., and Ferreia M. G. S., “E. I. S. Evaluation of Attached and Free Polymer Films,” Prog. Organ. Coat., 2000, 38, 1-7.