SOUR CORROSION INHIBITION USING FACILE-DESIGNS OF SCHIFF BASE POLYMERS FOR CARBON STEEL PIPELINES

Abstract

As an economic and applied materials, three Schiff base polymers which have the structure of -CH=N- double bond were synthesized by facile polycondensation reactions and applied as corrosion inhibitors in sour media. Because of their enhanced film-forming ability and multifunctionality, poly Schiff bases possess higher protective barrier features than other corrosion inhibitors. FTIR, 1HNMR, GPC, and TGA were used to characterize the as-synthesized polymers. These polymers are efficient and economic corrosion inhibitors for sour media. Polarization resistance method was used to test the corrosion rate mode, where the electrochemical impedance spectroscopy (EIS) was investigated. Field emission SEM and EDX were used to investigate the morphology of corrosion and surface composition of carbon steel samples. These outstanding poly Schiff base materials demonstrated a high corrosion inhibition, and are therefore recommended as a guide for the design of inhibitor in sour condition. The electronic structures and molecular geometry were investigated through quantum calculations which indicated the chemical reactivity and kinetic stability of compounds. The PSB2 presented the most profound sour corrosion inhibition properties when tested through electrochemical techniques. Its 300 ppm dosage yielded 90.21 % and 86.19 % inhibition efficiencies in potentiodynamic polarization and EIS measurements, respectively