Inhibition of Aluminum Corrosion in Hydrochloric Acid by n-, Di-n- and Tri-n-Butylamines

Abstract

Weight losses of aluminum in hydrochloric acid are diminished in the ranges 16–75 for n-; 40–90 for di-n~ and 50–98percent for tri-n-butylamine. Inhibitor efficiency increases with acid concentration up to 1.25 or 1.5 N, depending on the inhibitor and is practically constant thereafter. Efficiency increases with increased inhibitor concentration up to a certain value, then remains constant. Optimum inhibitor concentration depends on acid concentration and immersion period. Experimental results indicate corrosion of pure aluminum in hydrochloric acid solutions is essentially under cathodic control and inhibition by amines is by adsorption on cathodic areas. A similar mechanism is indicated for aluminum alloyed with manganese.

Adsorption and thermodynamic studies of the corrosion inhibition effect of Rosmarinus officinalis L. leaves on aluminium alloy in 0.25 M HCl and effect of an external magnetic field

“…With only a single activated complex exists in the slowest step of the reaction, that is, the rate determining step, this means the interaction between molecules of the inhibitor and that of the absorbent dissociative owing to the decrease in disorder. This result is similar to that reported by Abdallah et al (2013).…”

“…Figure 7 shows the plots of values of Calculated values of 0  o H were obtained and found to be higher in the presence of R. officinalis L. leaves extract than in its absence. This suggests that the Aluminium dissolution process is endothermic (Lyubchik et al, 2011) and agrees with results obtained by Abdallah et al (2013) and Ating et al (2010).…”

“…In corrosion science, there is a fundamental quantity, the corrosion rate quantifies this degree of dissolution (Abdallah et al, 2013 ,  is the average density of all the coupons in g/mm 3 , A is the area of the Al coupon in mm 2 , and t is the exposure time in hours.…”

“…is an important parameter in adsorption thermodynamic studies as it determines the temperaturedependence of the corrosion rate. It gives the minimum amount of energy required for the onset of an adsorbateadsorbent interaction (Saha and Chowdhury, 2011 (Abdallah et al, 2013;Manimegalai and Manjula, 2015): natural log of Equation 10 yields:…”

“…In addition, aluminium is generally non-toxic, paramagnetic, and possesses high resistance to atmospheric or environmental corrosion Davis (1993). The corrosion resistance of aluminium is due to its ability to readily passivate, to form a tough, inert thin oxide film on its surface almost immediately when exposed to the atmosphere (Noor, 2009;Hansson 2011;Sangeetha et al, 2013) thereby reducing its susceptibility to corrosion (Abdallah et al (2013).…”