Corrosion inhibition of mild steel in sulphuric acid using a bicyclic thiadiazolidine

BANERA MAURO J; JOSÉ A. CARAM; CLAUDIO A. GERVASI; MARÍA V. MIRÍFICO

JOURNAL OF APPLIED ELECTROCHEMISTRY

SPRINGER

Lugar: Berlin; Año: 2014 vol. 44 p. 1337 - 1344

0021-891X

The inhibitory effect of 3a,6a-diphenyltetrahy-9 dro-1H-imidazo [4,5-c] [1, 2, 5] thiadiazole-5(3H)-thione 2,2-dioxide (TTU) on the corrosion behaviour of mild steel in 0.5 M H2SO4, at (30 ± 0.5) C was studied by gravimetric, potentiodynamic polarization, electrochemical impedance spectroscopy, and scanning electron microscopy measurements. The effect of inhibitor concentration on the corrosion rate, surface coverage and inhibition efficiency is investigated. Results show that TTU exerts a strong inhibiting effect on mild steel corrosion and acts as a18 cathodic-type inhibitor. TTU does not affect the mechanism of the cathodic reaction while the anodic reaction mechanism changes upon addition of the inhibitor. Possible mechanistic pathways for the inhibition process are proposed. The inhibition efficiency of TTU may be due to either the adsorption of inhibitor molecules building a protective film or the formation of an insoluble complex of the inhibitor with metal cations. TTU adsorption obeys the Langmuir model.