Preparation Of Corrosion Inhibitor For Aluminium In Sodium Hydroxide Solution

Content:The metal aluminium have the eximious characteristics of the fine appearance,the small density,the excellent transmission of the heat and the electricity, the resistance to erode,avail of the entironment and so on.The equipment of the aluminium and the alloy are widely applied to the every field in the national economy, especially in chemical and petrochemical industry,such as,condensators,cisterns, tank cars,tubings and so on.They are also vastly maken use of the architecture,traffic and light industry.The mass of the researchs about the aluminium inhibitors in Sodium hydroxide have been taken by the earlier scientists.There are the inorganic salts,such as,the silicate,the chromate,applying in Sodium hydroxide as the aluminium inhibitors in the early stage.The organic macromolecule compounds play an important part in Sodium hydroxide to restrain the corruption of the aluminium hereafter,at the same time,the reseachers find that the organic compound are effective used to restrain corruption of the aluminium.We must prepare a new complex corrosion inhibitor to change the condition of limitation about the single composite in order to resist the factors of the impurity and the temperature in the work.The corrosion velocity and corrosion inhibition efficiency of many kinds of compound for aluminium in 5%Sodium hydroxide was studied using the weight-loss method,then some kinds of compounds with certain corrosion inhibition effect have been got in 5%Sodium hydroxide solution.In these compounds resorcin,propiolic alcohol,furan-formaldehyde and sodium tripolyphosphate are selected as research object.Their corrosion inhibition action for aluminium was studied with different temperatures in 5%Sodium hydroxide by adsorption theory and electrochemical polarization-curve method,the mechanism of corrosion inhibition action was analyzed and the thermodynamic functions during the adsorption process.The results indicated that the single molecule layer of these compounds adsorbed on the surface of aluminium and almost followed Langmiur isothermal equation.The adsorption procedure of resorcin,propiolic alcohol,furan-formaldehyde and sodium tripolyphosphate was a heat-absorbing reaction.The adsorption ability and corrosion inhibition efficiency increased when temperature increased.The corrosion inhibition action of this composite corrosion inhibitor has been evaluated by using weight-loss method,electrochemical polarization-curve method and scanning electron microscopy techniques.The corrosion rate of aluminium in 5% Sodium hydroxide has been determined with different concentration of 5%Sodium hydroxide,different temperature and different time.The SEM photos indicated that no signal of was found under different corrosion condition.It shows that the composite corrosion inhibitor is an excellent corrosion inhibitor for aluminium in 5%Sodium hydroxide solution.