アミン類を主剤とする防食剤の研究 (第23報)

Abstract

Corrosion-inhibition effects of several acid amides, i.e. palmitic acid amide (I), N-methyl palmitic acid amide (II) and N-dimethyl palmitic acid amide (II), which show difference in degree of association were studied. C-O stretching frequency in infra-red spectrometory indicated that I is entirely combined with hydrogen bond, II is combined at large with hydrogen bond, and III is not to be combined at all. The results of corrosion tests conducted with filmed mild steel test coupons dipped into 1% carbon tetrachloride solution showed that the effectiveness of thea mides as inhibitors was in order of III>II>I. In 0.1% dioxane solution, however, three amides were not found to be bonded with hydrogen and corrosion-inhibition test conducted with filmed mild steel test coupons in this solution was appeared to be in order of I>II>III. These results indicated that the unshared pair of electrons which required for chemisorption were blocked with the hydrogen bond.When the effect of the hydrogen bond was removed by lowering the concentration of carbon tetrachloride solution or increasing the adsorption temperature, the inhibition effect was found to be in order of I>II>III. Furthermore same result in the inhibition effect was obtained when applying dispersant to disperse the amides into water and this meant the dispersant was also effective in dissociating the amides.