High Performance Organic Coatings of Polypyrrole Embedded with Manganese Iron Oxide Nanoparticles for Corrosion Protection of Conductive Copper Surface

Herein, we report the formation of organic composite coating consists of epoxy (EP) reinforced para toluene sulphonic acid (PTSA) doped polypyrrole (PPy)–manganese iron oxide (MnFe₂O₂) as an efficient corrosion inhibitor for copper substrates. The PTSA doped PPy:MnFe₂O₂ nanocomposite was synthesized via in situ polymerization of PPy in the presence of MnFe₂O₂ nanoparticles. Structural features of the prepared samples were characterized through scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy and thermogravimetric analysis (TGA). The PTSA doped PPy:MnFe₂O₂ nanocomposite shows excellent conductivity and improved dielectric performance in comparison to pure PPy. The anti-corrosion performance of this organic composite coating was analyzed through Tafel polarization curves, open circuit potential (OCP), corrosion resistance, impedance spectroscopy and oxygen permeability barrier tests. The nanocomposite coating on copper substrate shows superior corrosion protection efficiency (99%) in comparison to pure epoxy (22%). Adhesion strength of the nanocomposite coating shows significant enhancement due to strong dispersions of MnFe₂O₂ nanoparticles in the host matrix. Owing to its improved conductivity, excellent anti-corrosion performance along with superior mechanical properties, the organic nanocomposite coating reported in this work can potentially be used to protect the conductive copper surfaces from harsh corrosive environments.