Inhibiting effects of butyl triphenyl phosphonium bromide on corrosion of mild steel in 0.5Â M sulphuric acid solution and its adsorption characteristics

Potentiostatic polarisation measurements showed that passivation was observed only for lower BuTPPB concentrations (10−5 and 10−7 mol l−1) for the mild steel in 0.5 M H2SO4. IR and SEM investigations also confirmed the adsorption of BuTPPB on the mild steel surface in 0.5 M H2SO4 solutions. The molecular parameters obtained using PM3 semi-empirical method, were correlated with the experimentally measured inhibitor efficiencies.