Corrosion inhibition of aluminum alloy in H3PO4 solution using para-thiazolidinone derivatives

Abstract

The influence of p-thiazolidinone derivatives as corrosion inhibitors for aluminum alloy in 3 MH3PO4 solution has been studied by weight-loss and galvanostatic polarization techniques. A significant decrease in the corrosion rate of aluminum was observed in the presence of these investigated inhibitors. The inhibition efficiency of these derivatives increases with increasing the inhibitor concentration but decreases with increasing temperature. The inhibition efficiency values of the examined derivates follow the order: 5(-4-methoxyphenylazo)-3-phenylamino2-thioxo-4 thiazolidinone (e) > 5(-4-methylphenylazo)-3-phenylamino-2-thioxo-4thiazolidinone (d) > 5(-4-hydrophenylazo)-3-phenylamino-2-thioxo-4-thiazolidinone (c)> 5(-4-chlorophenylazo)3-phenylamino-2-thioxo-4thiazolidinone (b) > 5(-4-nitrophenylazo)-3-phenylamino-2-thioxo-4-thiazolidinone (a). The galvanostatic polarization studies revealed that these compounds behave as mixed-type inhibitors. The effect of temperature on corrosion inhibition has been ...