The synergistic effect of zinc acetate on the protective behavior of sodium lignosulfonate for corrosion prevention of mild steel in 3.5 wt% NaCl electrolyte: Surface and electrochemical studies

In the present study, the synergistic behavior of sodium lignosulfonate-zinc acetate (SLZA) system and its consequent effect on the corrosion prevention of mild steel in the 35 wt% NaCl electrolyte was studied. The electrochemical and surface analyses were carried out to understand the actual corrosion inhibition action of the SLZA system. The results of electrochemical studies showed that the uniform corrosion of mild steel was synergistically suppressed due to the co-inhibition of sodium lignosulfonate (SL) and zinc acetate (ZA). The synergism parameter was about 9 and the total resistance of mild steel was >400 k Omega.cm(2) in the co-presence of SL and ZA. Also, the calculated inhibition efficiency of SLZA system was about 96%. A corrosion protective system with such excellent performance is considerably rare in the literature. The co-deposition of surface barrier film consists of SL-based complexes and zinc-containing compounds was proposed as the main corrosion prevention mechanism in the presence of the SLZA system based on the results of XPS and SEM-EDS analyses. (C) 2020 Elsevier B.V. All rights reserved.