Conducting polyaniline/nano-zinc phosphate composite as a pigment for corrosion protection of low-carbon steel
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Zinc phosphate (Zn3(PO4)2) nanocrystals were synthesized and used for making conducting polyaniline/nano-zinc phosphate composite by chemical oxidative method. The product was characterized by UV–visible absorption spectroscopy. The crystal structure, morphology and thermal stability of the product were studied by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and thermo gravimetric analysis, respectively. The epoxy-based paint containing conducting polyaniline/nano-zinc phosphate composite pigment was applied on low-carbon steel samples. Corrosion protection performance of the painted low-carbon steel samples in 3.5 mass % sodium chloride solution was evaluated using electrochemical technique. Transmission electron microscopic image revealed the formation of core shell structure of the composite. Composite was found to be more thermally stable than the conducting polyaniline. The corrosion rate of conducting polyaniline/nano-zinc phosphate-painted low-carbon steel was found to be 5.1 × 10−4 mm per year, about 34 times lower than that of unpainted low-carbon steel and 10 times lower than that of epoxy nano-zinc phosphate paint-coated steel. The study reveals the possibility of using conducting polyaniline/nano-zinc phosphate as a pigment for corrosion protection.
KeywordsConducting polyaniline/nano-zinc phosphate Low-carbon steel Corrosion protection Conducting polymer Passivation Inhibiting phosphate ions
The author thanks Prof. N.B. Dhokey, Head, Department of Metallurgy and Materials Science, College of Engineering, Pune, 411005 (M.S.) India for providing facilities for the work and Prof. B.B. Ahuja, Director, College of Engineering, Pune, 411005 (M.S.) India for his encouragement.
- Al Dulami AA, Hashim S, Khan MI (2011) Corrosion protection of carbon steel using polyaniline composite with inorganic pigments. Sains Malaysiana 40:762Google Scholar
- Deshpande PP, Sazou D (2015) Corrosion protection of metals by intrinsically conducting polymers. CRC Press, Boca Raton, pp 159–183Google Scholar
- Deshpande PP, Peshwe DR, Pathak SU (2001a) A note on electrochemical synthesis of conducting polyaniline films on low alloy steel. Trans Indian Inst Metals 54:179–183Google Scholar
- Deshpande PP, Peshwe DR, Pathak SU (2001b) Corrosion control by an organic metal: a review. J Inst Eng (India) Series A 82:33–36Google Scholar
- Gvozdenovic M, Jugovic B, Jambrec D, Stevanovic J, Grgur B (2012) Application of polyaniline in corrosion protection of metals. Zasta Materijala 53:353–360Google Scholar
- Trivedi DC (1997) Polyanilines. In: Nalwa HS (ed) Hand book of organic conductive molecules and polymers. Wiley, Chichester, pp 506–566Google Scholar