تحضير وتشخيص وتقييم بعض معقدات قواعد شف لايوني النحاس والموليبدينوم كمثبطات تاكل لسبيكة حديد الصلب الكربوني في الوسط الحامضي == Preparation, Characterization and Evaluation of Some Schiff Base’s Complexes of Copper and Molybdenum Ions as Corrosion Inhibitors for Carbon Steel Alloy in Acidic Medium
Author name:
محمد علي مهدي الحلفي
Supervisor name:
زكي ناصر كاظم | هادي زيارة محمد
General topic:
Chemistry
Specific topic:
Chemistry
Degree:
Master
University:
University Of Basrah - College Of Science - Chemistry Department
Language:
Arabic
University location:
Basrah
First pages:
25T1610 - p.pdf
Abstract:
In this study, two types of Schiff base were prepared as ligands L1, L2, by reaction of an equal number of moles of tris(hydroxymethyl) methyl amine with salysildehyde and vanillin in a methanolL1 : ((E) - 2 - ((2 - hydroxybenzylidene) amino) - 2 - (hydroxymethyl) propane - 1,3 - diol) L2 : ((E) - 2 - ((4 - hydroxy - 3 - methoxybenzylidene) amino) - 2 - (hydroxymethyl) propane - 1,3 - diol).The Cu(II) and Mo(VI) complexes were prepared to produce the : - A1 : tetrakis(μ3 - 2 - {[1,1 - bis(hydroxymethyl) - 2 - oxidoethyl] iminomethyl} - phenolato) tetrakis [aqua copper(II)].A2 : tetrakis(μ3 - 2 - {[1,1 - bis(hydroxymethyl) - 2 - oxidoethyl] iminomethyl} - 2 - meth - oxy} - phenolato) tetrakis [aqua copper(II)].B1 : (E) - 2 - methyl - 2 - ((2 - ((methyl(l1 - oxidanyl) dioxomolybdenio) oxy) benzylidene) amino) propane - 1,3 - diol).B2 : (E) - 2 - ((4 - hydroxy - 3 - ((methyl(l1 - oxidanyl) dioxomolybdenio) (methylene) - l4 - oxidanyl) benzylidene) amino) - 2 - methyl) propane - 1,3 - diol).The ligands and complexes were characterized by Fouries transformer infrared FTIR, UV and NMR techniques.All these techniques insisted that the ligands and their complexes were prepared successfully.On the other hand, the four complexes A1, B1, A2 and B2 were evaluated as corrosion inhibitors against a corrosive environment of 0.1M of hydrochloric acid at constant temperature of 25°C and different concentration for each one of the above complexesIIrange (10 - 50) ppm and it has been found that the efficiency of inhibition at a temperature 25℃ are not highly efficient, the KI was added in order to increase the efficiency of these inhibitors values to these inhibitors.The inhibition efficiency for all inhibitors was increased in presence of KI compared with the absence of it.On the other hand, the complexes of copper i.e., A1 and A2 have higher efficiency than molybdenum complexes i.e. (B1 and B2) this can be attributed to the ability of copper ion (II) to donate the electron density to the ligand by back donation competence these behaviour compared with molybdenum ion (VI) that has not the ability that present in copper ion, Also studied the effect of concentration of the inhibitor prepared in other temperatures change separately and these grades are within the range (35 - 55) ℃ has been observed that efficiency does not increase either the existence of KI with the inhibitor, or without, but the decreasing efficiency with increasing temperature, means that the inhibitor adsorbed physically on carbon steel alloy.The functions thermodynamic adsorption such as free energy, enthalpy and entropy were studies depending on the adsorbent layer θ on the surface of the carbon steel alloy. The data was shown all the complexes are subject to model for Langmuir adsorption was shows the free energy negative values means that the interaction is spontaneous and notes total increasing of the temperature less than the negative value of the free energy leading to towards the is non - spontaneous. The negative values of enthalpy means that the interaction is exothermic, the negative value of the entropy of adsorption ΔSads and gradually moving toward positive values with a high temperature means that the random was less in high temperature. Also the kinetics of corrosion in the absence and present of the inhibitor was studied with KI in (0.1) M HCl. The activation energy and other thermodynamic function such as enthalpy and entropy and free energy was shown that the higher activation energy in presence inhibitor and it was higher in presence of KI with inhibitor. This is an indication that the interaction of corrosion is small in the presence of these inhibitors.
