Synergistic effect of halide ions on the corrosion inhibition of aluminum in acidic medium by some polymers

Abstract

ABSTRACT:The corrosion inhibition of aluminum in H 2 SO 4 in the presence of polyvinyl alcohol (PVA) and polyethylene glycol (PEG) and the effect of addition of halides (KCl, KBr, KI) was studied using the hydrogen evolution technique at 30 and 40°C. Inhibition efficiency (%I) increases with concentration of PVA and PEG--but with PEG having higher %I. The %I decrease with increase in temperature from 30 to 40°C in the absence and presence of inhibitor and halides. PVA and PEG were found to obey Freundlish adsorption isotherm. Phenomenon of physical adsorption is proposed from the obtained E a , ⌬G ads , and Q ads values obtained. The synergism parameters (S I ) obtained were found to be greater than unity for both PVA and PEG, which indicates that the enhanced inhibition efficiency caused by the addition of halides is only due to synergism.

Corrosion Inhibition Studies on Mild Steel in Acidic Media with 2-Hydroxy-4ʹ-methoxy Chalcone

“…The apparatus and procedure followed for weight loss method was similar to that earlier reports [14][15][16][17] . In the weight loss method, the progress of the corrosion reaction was monitored by determining the weight loss of the coupons (obtained as the differences in the weight of the coupons after immersion in solutions of the system and the original weight of the coupons) at fixed time intervals.…”

Mild steel corrosion inhibition by acid extract of leaves ofHibiscus sabdariffaas a green corrosion inhibitor and sorption behavior

“…The leaves are washed with deionized water and then dried in oven at 80 ± 1°C for a period of one hour. A 15 g of dried leaves is taken and to that 10 mL each of H 2 SO 4 , HCl, and HNO 3 are added, along with this 300 mL of double-distilled water is added (33). The mixture is boiled for a period of 30 minutes and then kept aside for 16 hours.…”

“…Requisite quantity of inhibitor is added to 250 mL plastic beakers containing 100 mL of synthetic corrosion medium and mild steel (33). The bottles are maintained at temperature 30 ± 1°C for all experiments.…”

Corrosion Inhibition of Mild Steel in 1 M H2SO4 by Polyvinyl Pyrrolidone and Synergistic Iodide Additives

“…It is thought that the initial specific adsorption of the halide ions on the metal surface facilitates the adsorption of organic cations by forming intermediate bridges between the positively charged metal surface and the positive end of the inhibitor. A few reports from our laboratory highlighted the synergistic effect of halide ions on the corrosion of mild steel in acidic solution [15][16][17], while the synergistic inhibition between organic compounds and iodide ions has been reported by some research groups [18][19][20][21][22]. However, reports on synergistic influence of halide ions and polymers are very scanty [23,24].…”