Synthesis of new epoxy glucose derivatives as inhibitor for mild steel corrosion in 1.0 M HCl, Experimental study: Part -1

A two non-toxic biodegradable epoxy glucose derivatives, namely 5,6-anhydro-3-O-octa-1,2-O-isopropyli-dene-α-D-glucofuranose (EGC8) and 5,6-anhydro-3-O-butadecyl-1,2-O-isopropylidene-α-D-glucofuranose (EGC14), were prepared and characterized by using spectroscopic measurements. These products were tested for mild steel corrosion inhibition in 1.0 M HCl using electrochemical measurements. It is shown that these epoxy glucose derivatives affect the cathodic branches with a shift in the cathodic direction (cathodic - type).  So, it found that their inhibition efficiency arise with concentrations to achieve a maximum of 93.2 % and 93.48 % at 10-3 M of EGC8 and EGC14, respectively, and they depends to the carbon number chain following the order : EGC14 > EGC8. Indeed, it is found that these compounds adsorb according the Langmuir’s adsorption isotherm. On the other hand, the temperature effect on the inhibition efficiency of the epoxy glucose derivatives indicated that they take them at high-rise temperature. In addition, the calculated kinetic and thermodynamic parameters have shown that EGC8 act via physical adsorption while EGC14 act via chemical adsorptions, and their process are endothermic and spontaneous.