Synergic effect of methyl acrylate and N-cetylpyridinium bromide in N-cetyl-3-(2-methoxycarbonylvinyl)pyridinium bromide molecule for X70 steel protection

• A new inhibitor was built by covalently jointing methyl acrylate and cetylpyridinium bromide.
• Its inhibition efficiency for X70 steel is about four times that of MA and 20% higher than that of CPB.
• Its inhibitive performance is well explained by the parameters from theoretic calculation.
• MA moiety in the inhibitor may donate electron while CPB moiety accepts electron on iron surface.

N-cetyl-3-(2-methoxycarbonylvinyl)pyridinium bromide (designated as MAP) has been synthesized by covalently binding methyl acrylate (MA) and N-cetylpyridinium bromide (CPB). The inhibition efficiency of MAP (97.3%) was seven times more than that of MA (13.6%), but the concentration was 1/10 that of MA. The adsorption of MAP on X70 steel surface increased charge transfer resistance as well as activation energy of metal corrosion, and inhibited both anode and cathode. The interaction energy of the inhibitors with iron and molecular volume were in the order of MAP > CPB > MA, suggesting the same order in inhibition efficiency.

The difference of EHOMO, ELUMO and ΔE for the three compounds suggesting the synergic effect of MA moiety and CPB moiety in MPA.Figure optionsDownload as PowerPoint slide