Corrosion protection of cold-rolled steel with alkyd paint coatings composited with submicron-structure types polypyrrole-modified nano-size alumina and carbon nanotubes

► Alumina/carbon nanotube (CNT) supported polypyrrole (PPy) particles were prepared. ► Various paint compositions with alkyd binder were immersion tested. ► Alumina-supported PPy based coating provided steel protection in NaCl solution. ► Polyelectrolyte modified CNT embedded coating afforded long-term stable protection. ► sulphonated CNT loaded coating indicated firm corrosion resistance in HCL solution. ► Results are interpreted on the basis of nano and microstructure of the particles.