Chemical Engineering Communications · 2008 · 32 citations · 9 references
Natural SciencesMaterials EngineeringMaterials ScienceCorrosion ScienceElectrochemistrySurface ChemistryCorrosion ControlCorrosion InhibitorsCorrosion MechanismsCorrosion ProtectionCorrosion ResistanceCorrosion-resistant MaterialsCorrosion Inhibition AssessmentCorrosion Inhibition MechanismsCorrosion Inhibitor EffectsCorrosion Inhibitor EvaluationCorrosion Rate ReductionLangmuir Adsorption ModelMixed-type InhibitorsTemperature Effects On Inhibitor Performance
The effect of some low molecular weight straight-chain diamines to inhibit the corrosion of SS type 304 in 1 M HCl solution is examined by weight loss and galvanostatic polarization techniques. The inhibition efficiency increases with increasing the number of carbon atoms in the chain up to 8 carbons, but at higher than 8 carbon atoms (12 carbons) it decreases again. These diamine compounds act as mixed-type inhibitors, but the cathode is more polarized than the anode when an external current was applied. The corrosion rate in the presence of the investigated diamine compounds was found to increase with increasing the temperature and decrease with increasing the concentration of these compounds. Activation parameters for the corrosion of SS in 1 M HCl were calculated and showed that corrosion was much reduced in the presence of inhibitors. The adsorption of these compounds on SS from 1 M HCl solution obeys the Langmuir adsorption isotherm. The synergistic effect of KI on the inhibitive efficiency of the investigated diamine compounds was also studied.
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