Synthesis, identification and study of some new azo dyes as corrosion inhibitors for carbon-steel in acidic media

Abstract EN

The effect of some mono azo dyes compound on the dissolution of C-steel in 0.5M HCl solution was studied using weight loss and galvanostatic polarization techniques .The inhibition efficiency of inhibitor increases with concentration to attain (63.35 %,73.28 %) of A1 and A2 at concentration 5 × 10−3 M, time 240 min and temperature 30°C.

Temperature effect on the corrosion behavior was studied at temperature range from 30-60°C, the results showed that inhibition efficiency increased with increasing temperature to attain (75,50 %, 83.54 %) of A1and A2 at concentration 5 × 10−3 M, time 240 min and temperature 60˚C.The effect of temperature on the rate of corrosion in the absence and presence of this compound was also studied.

The activation energy and thermodynamic parameters governing the adsorption process were calculated and discussed.

Polarization curves revealed that the studied inhibitors represent mixed–type inhibitors.

Adsorption of inhibitors was found to obey Langmuir isotherm and was isotherm chemisorption type.