Abstract Functional copolymers are often used as protective coating against corrosion. In this research article, we have applied poly(NVI-co-EMA) coating over the mild steel surface which provides barrier protection against corrosion in aggressive environment. Hydrophobic nature of the copolymer film may augment the corrosion resistance behavior and thermal stability of the copolymer also influences the corrosion protection. Thus, the coating precluded the corrosive elements and corrosion products from diffusing through the coating. EIS technique revealed that the mild steel coated with hydrophobic copolymer film, which is immersed in 3% NaCl solution provides excellent protection from corrosion. Further, it is evidenced by protection efficiency of the copolymer which is greater than 90%. The results from surface analysis techniques like SEM, AFM and FTIR also supports and confirms a very thin film on the metal surface with excellent anticorrosion effects.