Synergistic effect of gum arabic and sodium alginate for the corrosion inhibition of pipeline steel in H2SO4 solutions

• T. Khair¹, Y. Abakumova¹, D.A. Kazantseva² and O.S. Zueva¹

¹ Kazan State Power Engineering University, Krasnoselskaya str. 51, 420066 Kazan, Russia
² Bauman Moscow State Technical University, Department of Electronic Technologies in Mechanical Engineering, 2 Baumanskaya str. 7, 105005 Moscow, Russia

Abstract: This paper proposes a new composite natural corrosion inhibitor based on gum arabic with addition of sodium alginate. Gum arabic, primarily composed of branched polysaccharide chains and a small amount of protein, is an environmentally safe and sustainable anticorrosive material known for its exceptional effectiveness with respect to steel when used in acidic HCl medium and in some other environments. However, in an H₂SO₄ environment, due to the lack of halogen ions that contribute to the formation of a durable protective coating on the surface, its effectiveness is reduced by half. To eliminate this drawback, we proposed adding a natural inhibitor with a different mechanism of protective action, such as the linear anionic polysaccharide sodium alginate, extracted from seaweed. A combination of methods (mass loss measurements, optical, scanning and transmission electron microscopy, electrochemical methods) demonstrated that in the presence of a composite inhibitor based on gum arabic with the addition of sodium alginate, corrosion inhibition efficiency reaches 97%. The primary mechanism of gum arabic inhibition effect is the physical adsorption of their swollen macromolecules. In the case of inhibition by sodium alginate, free Fe²⁺ ions formed during the oxidative dissolution of low-carbon steel crosslink the alginate chains through the formation of chelate complexes. Adsorption of the resulting structures onto metal surface blocks the active sites and reduces the reactivity of the metal surface. Since the inhibition mechanisms of gum arabic and sodium alginate differ, their combined use results in a synergistic effect, in which both mechanisms act independently, promoting surface protection.

Keywords: pipeline steel, corrosion, protection, inhibitor, gum arabic, sodium alginate

Int. J. Corros. Scale Inhib., 2026, 15, no. 2, 364-385
doi: 10.17675/2305-6894-2026-15-2-21

Download PDF (Total downloads: 40)

Back to this issue content: 2026, Vol. 15, Issue 2 (pp. 1-... (in progress))