Effect of halide ions on the corrosion inhibition of aluminium in alkaline medium using polyvinyl alcohol

Abstract

The corrosion inhibition of aluminum in NaOH in the presence of polyvinyl alcohol (PVA) at 30 and 408C and the effect of addition of halides (KCl, KBr, KI) were studied using weight loss and hydrogen evolution methods. Results obtained showed that PVA acts as a corrosion inhibitor in the alkaline environment. The inhibition efficiency increased with increase in concentration of PVA and synergistically increased on the addition of the halides but however decreased with rise in temperature. The phenomenon of physical adsorption is proposed from the obtained E a and Q ads values. PVA was found to obey Freundlich and Frumkin adsorption isotherms. The increase in inhibition efficiency I (%), surface coverage y values as well as synergistic parameter, S I were found to be in the order, which clearly indicates that the radii and electronegativity of the halides play a significant role in the adsorption process.

Corrosion Behaviour of Aluminium in the Presence of an Aqueous Extract of Hibiscus Rosa-sinensis

“…To prevent the corrosion of aluminium in acid medium, inhibitors such as imidazoline derivatives [1], Capparis decidua [2], polyethylene glycol and polyvinyl alcohol [3], delonix regia extract [4] and Sansevieria trifasciata extract [5], have been used. In alkaline medium, polyvinyl alcohol [6], gongronema latifolium extract [7], bismark brown dye [8], methyl orange [9] and onion extract [10] have been used as corrosion inhibitors to prevent corrosion of aluminium. Corrosion inhibition of aluminium using super hydrophobic films [11], structure and stability of adhesion promoting aminopropyl phosphonate layers at polymer/aluminium oxide interfaces [12], microbially influenced corrosion of zinc and aluminium [13], corrosion inhibition of aluminium by rare earth chlorides [14], effects of inhibitors on corrosion behaviour of dissimilar aluminium alloy friction stir weld [15], a high throughput assessment of aluminium alloy corrosion using fluorometric methods [16], surface modification for aluminum pigment inhibition [17] and filiform on 6000 series aluminium [18], have been investigated.…”

Synergistic Influence of Gum Arabic and Iodide Ion on the Corrosion Inhibition of Aluminium in Alkaline Medium

“…Studies involving organic inhibitors and synergistic effect of halide ions generally, and iodide ions in particular in alkaline medium are rather scanty [25,26]. A recent contribution in this regard in our laboratory involves the investigation of effect of halide ions on the corrosion inhibition of aluminium in NaOH using synthetic polymers, namely polyvinyl alcohol (PVA) and polyethylene glycol (PEG) [27,28]. However, no reports exist, to the best of our knowledge, on the effect of iodide ion on the corrosion of aluminium in alkaline environment using naturally occurring polymers.…”

Nano-Silicate from Paddy Waste as Natural Corrosion Inhibitor

“…This shows that adsorption process has occurred spontaneously [31]. Huge value of K ads characterizes the stability and strength of the interaction of the inhibitor molecules that has been adsorbed on the surface of metal/steel.…”