engleski

Inhibition efficiency of natural compaunds on tin corrosion in salt solutions

In this paper the effect of some natural compounds on the electrochemical and corrosion behaviour of tin in sodium chloride solution was investigated. For this purpose, model salt solutions containing sodium chloride (3 - wt %) and added cysteine, methionine, lysine and S-methyl-L-cysteine at the concentrations from 10-5 to 10-2 wt %, were prepared. As a control electrolyte 3-wt % sodium chloride solution was used. From the potentiostatic polarisation data (using the standard three-electrode system) corrosion current (icorr.), corrosion potential (Ecorr.) and polarisation resistance (Rp) were calculated. The highest inhibition efficiency of methionine, lysine and S-methyl-L-cysteine ranged from 48 % to 79 %. The presence of cysteine, except at the concentration of 10-3 % in sodium chloride solution, acted as corrosion accelerator. Generally, a suitable well fitting linear correlation between amino acids concentration and investigated parameters (pH, k, icorr., Ecorr., Rp) was obtained.

Corrosion inhibitors; cysteine; lysine; methionine; S-methyl-L-cysteine; sodium chloride; tin

nije evidentirano