Designing of corrosion resistant epoxy coatings embedded with polypyrrole/SiO2 composite

•Epoxy coating designed with different wt% loading of polymer composite (PCs).•High corrosion protection efficiency (% P.E.) is achieved for epoxy with PCs.•% P.E. of 99.99 is achieved for epoxy with 3wt% loading of PCs.•Extended corrosion is not noticed for epoxy coating with PCs in salt spray tests. Polypyrrole/SiO2 composite was synthesized by chemical oxidative polymerization of pyrrole using FeCl3. The synthesized polymer composite was loaded in epoxy resin to develop coatings for mild steel substrates using powder coating technique. SEM and TEM images reveal homogenous dispersion of SiO2 particles in polypyrrole matrix. TGA analysis confirms good thermal stability of the polymer composite. Tafel polarization and electrochemical impedance spectroscopy (EIS) results exhibit remarkably high corrosion protection efficiency of epoxy coatings with polymer composite in 3.5% NaCl solution. Corrosion studies of coatings with an artificial defect reveal the passivation of defect by the polymer composite present in the epoxy coatings. Salt spray test results revealed superior corrosion resistance offered by the polymer composite.