The present paper shows the effects produced by the substitution of the acetylenic hydrogen atom with the iodine atom on the inhibiting characteristics of alkynols of increasing aliphatic chain length towards Armco iron acid corrosion. The tested substances are: 1-butyn-3-ol, 1-hexyn-3-ol, 1-octyn-3-ol and their corresponding 1-iodo-derivatives; the proof media: deaerated 1N HCl or H2SO4 solutions, at 70 °C. EIS technique has been used to monitor the evolution as a function of time of the inhibiting action of the these substances and potentiodynamic polarisation curve are recorded to determine their effects on the cathodic hydrogen evolution and the anodic iron oxidation reaction. In both acid media the inhibiting action of the alkynols increases by increasing the aliphatic chain length and the presence of the iodine atom extends such action. Furthermore, in sulphuric acid solutions the iodo-alcohols show higher inhibiting effects than the corresponding alkynols. It is reputed that the introduced halogen atom favours and stabilizes the chemisorption of the compounds onto the iron surface.
The inhibition of iron acid corrosion by means of acetylenic iodo-alcohols
FRIGNANI, Alessandro;MONTICELLI, Cecilia;TRABANELLI, Giordano
2000
Abstract
The present paper shows the effects produced by the substitution of the acetylenic hydrogen atom with the iodine atom on the inhibiting characteristics of alkynols of increasing aliphatic chain length towards Armco iron acid corrosion. The tested substances are: 1-butyn-3-ol, 1-hexyn-3-ol, 1-octyn-3-ol and their corresponding 1-iodo-derivatives; the proof media: deaerated 1N HCl or H2SO4 solutions, at 70 °C. EIS technique has been used to monitor the evolution as a function of time of the inhibiting action of the these substances and potentiodynamic polarisation curve are recorded to determine their effects on the cathodic hydrogen evolution and the anodic iron oxidation reaction. In both acid media the inhibiting action of the alkynols increases by increasing the aliphatic chain length and the presence of the iodine atom extends such action. Furthermore, in sulphuric acid solutions the iodo-alcohols show higher inhibiting effects than the corresponding alkynols. It is reputed that the introduced halogen atom favours and stabilizes the chemisorption of the compounds onto the iron surface.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
