Title:
Synergistic Inhibition of Polyethoxylated Sorbitan Monooleate and Benzoate on Chloride Accelerated Deterioration of Rebars Embedded in Mortars (Prepublished)
Author(s):
Raja Rizwan Hussain, Abdulrahman Alhozaimy, Abdulaziz Al-Negheimish, and Mshtaq Ahmed
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
benzoate; chloride; corrosion; mortar; polyethoxylated sorbitan monooleate; reinforcing bars
DOI:
10.14359/51751785
Date:
6/4/2026
Abstract:
Very effective synergistic protection of polyethoxylated sorbitan monooleate (PSM) with sodium benzoate (SBZ) is noted for chloride-accelerated deterioration of steel rebars embedded in mortars. Individual components exhibit an insignificant inhibitive effect on corrosion. The mixture of the two components of inhibitors at their optimized concentrations (0.025% PSM+0.25% SBZ) imparts protection on rebars of the order of 98% tested for long durations of exposure (900 days). The electrochemical impedance tests conducted at different durations of exposure show that inhibitive effects increased with an increase in exposure time. Morphology and energy-dispersive X-ray analysis performed by scanning electron microscopy of corrosion products accumulated on the rebars' surface after 900 days of exposure indicate the formation of a very compact film and a negligibly small presence of chloride. A phenomenal improvement in protective effect for the mixture of PSM and SBZ is attributed to the shielding effect of the former on benzoate anions. This increased the availability of the benzoate anion in the inner Helmholtz plane of the double layer formed at the corroding interface, leading to increased protection against corrosion.