CORROSION INHIBITION OF CARBON STEEL DURING ACID CLEANING PROCESS BY A NEW SYNTHESIZED POLYAMIDE BASED ON THIOUREA

摘要

In this work, a new polyamide (PA) based on thiourea and tartaric acid was synthesized and characterized by FT-IR spectroscopy. The efficiency of the new synthesized compound was evaluated as a corrosion inhibitor for carbon steel in 1Â M HCl solution using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques (EIS). The results show that PA is a good corrosion inhibitor and its inhibition efficiency reaches 90.6% at 250Â ppm. The values of the inhibition efficiency calculated from various techniques are in reasonably good agreement. The results obtained from EIS measurements show that the charge transfer resistance (R_t) increases with increasing inhibitor concentration, while the electrochemical double layer capacitance (C_dl) decreases. The inhibition process was attributed to the formation of an adsorbed film that protects the metal surface against corrosive medium. The adsorption of PA on the steel surface was found to obey Langmiur's adsorption isotherm. The mechanism of the adsorption process was discussed in the light of the chemical structure of PA. Scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDX) were used to confirm the existence of such protective film.View full textDownload full textKeywordsCarbon steel, Corrosion inhibitor, Energy dispersive X-ray analysis and impedance, Polarization measurements, Polyamide, Scanning electron microscopeRelated var addthis_config = { ui_cobrand: "Taylor & Francis Online", services_compact: "citeulike,netvibes,twitter,technorati,delicious,linkedin,facebook,stumbleupon,digg,google,more", pubid: "ra-4dff56cd6bb1830b" }; Add to shortlist Link Permalink http://dx.doi.org/10.1080/00986445.2011.596597