Corrosion behaviour of carbon steel in polyvinyl alcohol

Purpose – To evaluate the inhibition efficiency (IE) of polyvinyl alcohol (PVA) in controlling the corrosion of carbon steel immersed in neutral aqueous solutions containing 60 ppm of Cl−, in the absence and presence of Zn2+. To investigate the influence of sodium sulphite (Na2SO3), sodium dodecyl sulphate (SDS), pH and duration of immersion on the IE of PVA‐Zn2+ system. To analyse the protective film formed on the metal surface.Design/methodology/approach – The IE has been evaluated by weight loss method. The protective film was analysed by FTIR and fluorescence spectra.Findings – A formulation consisting of 100 ppm of PVA and 75 ppm of Zn2+ offered 81 per cent IE to carbon steel immersed in a solution containing 60 ppm of Cl−. A synergistic effect on inhibition of a combination of PVA and Zn2+ was observed during the tests. The protective film consisted of the Fe2+‐PVA complex and Zn(OH)2. It was found to be UV‐fluorescent. When SDS was added to the PVA‐Zn2+ system, the mixture showed maximum IE at the ...