In this work, some of new 2-benzylidenehydrazinecarbothioamide derivatives have been prepared by condensation of thiosemicarbazide and different substituted aromatic benzaldehydes in presence of glacial acetic acid to give compounds (1-6), these compounds have characterized by its physical properties and spectroscopic methods. This work also included theoretical study to prove the ability of these compounds as corrosion inhibitors; The program package of Gaussian 09W with its graphical user interface GaussView 5.0 had used for this purpose; the methods of Density Functional Theory (DFT) with basis set of 6-311G (d,p) / hybrid function of B3LYP and semiempirical method of PM3 have been used, the study included theoretical simulation to simulate the reactivity of these compounds as corrosion inhibitors for carbon steel in gas phase, aqueous medium and in acidic medium (acidic medium is a medium contains acid that able to protonate these compounds and change them to protonated form), some parameters have calculated in both previous methods such EHOMO, ELUMO, ΔEL-H, Ionization Potential (I), Electron Affinity (A), electronegativity (χ), Global Hardness (η), Atomic Charges, Dipole Moment (μ) and Fraction of Electron Transferred from Inhibitor Molecules to the Metallic Atoms (ΔN), the resulted parameters showed that these compounds are behaving as inhibitors for corrosion of carbon steel.
This research has presented a solution to the problem faced by alloys: the corrosion problem, by reducing corrosion and enhancing protection by using an inhibitor (Schiff base). The inhibitor (Schiff base) was synthesized by reacting of the substrates materials (4-dimethylaminobenzaldehyde and 4-aminoantipyrine). It was diagnosed by infrared technology IR, where the IR spectrum and through the visible beams proved that the Schiff base was well formed and with high purity. The corrosion behavior of carbon steel and stainless steel in a saline medium (artificial seawater 3.5%NaCl) before and after using the inhibitor at four temperatures: 20, 30, 40, and 50 C° was studied by using three electrodes potentiostat. The corrosion behavior was
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(6)
Corrosion rate tests were carried out on carbon steel under concentration cells conditions of oxygen and sodium chloride. The effect of aeration in one compartment on the corrosion rate of both coupled metals was determined. In addition, the effects of time and temperatures on the corrosion rate of both coupled metals and galvanic currents between them were investigated. Corrosion potentials for the whole range of operating conditions under concentration cell conditions were also studied. The results showed that under aeration condition, the formation of concentration cell caused a considerable corrosion rate of the Carbon steel specimens coupled in different concentrations of O2 and NaCl due to the galvanic effect
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The inhibitive effect of imidazol on the dissolution of Zn in (1M) HCl has been studied. The inhibion effect of imidazol ,protection efficiency and the corrosion rate of Zn in (1M) HCl were investigated at various concentrations (1x 10-3 – 5x10-3) M and tempearture range (285-328) K. The corrosion inhibitive of Zn by imidazol was studied using weight loss measurement and analytical titration of the amounts of dissolved zinc in acidic solution in presence and absent of imidazol. It was observed that imidazol led to protection efficiency reached to (88.93)% when (10)mM imidazol concentration was used. A linear relationship came true between (C/?) and (C); where (?) is the coverage of Zn surface by imidazol which could be obtained from
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New Fourteen compounds were synthesized in four steps. The first step included synthesis of 2-biphenyl fused ring of imidazo(1,2- a)pyrimidine from the reaction of 2-aminopyrimidine and biphenyl phenacyl bromide . The second step was introduced aldehyde group from the reaction of 2-biphenyl fused rings of imidazo(1,2-a)pyrimidine with POCl3 in presence of DMF and CHCl3. 3-Carbaladehyde derivatives of fused imidazo/pyrimidine was reacted with different aromatic amines to afford new Schiff bases. These new 3- imines derivatives was reduced by using sodiumborohydride to yield another new 3-aminomethyl-2-biphenyl imidazo (1,2-a)pyrimidine derivatives in moderate yield .Some new prepared compounds were identified by melting point, FT- IR , 13C-
... Show MoreIn this present work, [4,4`-(biphenyl-4,4`-diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)bis(2-methoxyphenl)(A1),4,4`-(biphenyl-4,4`-diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)diphenol(A2),1,1`-(biphenyl-4,4`-diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene) dinaphthalen-2-ol (A3)]C.S was prepared in 3.5% NaCl. Corrosion prevention at (293-323) K has been studied by using electrochemical measurements. It shows that the utilized inhibitors are of mixed type based on the polarization curves. The results indicated that the inhibition efficiency changes were used with a change according to the functional groups on the benzene ring and through the electrochemical technique. Temperature increases with corrosion current
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The corrosion behavior of carbon steel at different Temperatures and in water containing different sodium chloride
concentrations under 3 bar pressure has been investigated using weight loss method . The carbon steel specimens were
immersed in water containing (100,400,700,1000PPM) of NaCl solution and under temperature was increased from
(90-120ºC) under pressures of 3 bar. The results of this investigation indicated that corrosion rate increased with NaCl
concentrations and Temperature.
The Schiff base (E)-2-(((2-(1H-benzo[d]imidazol-2-yl) phenyl) imino) methyl)-4-methylphenol (Lb) ligand with some metals(II) ion such as; Co, Cu, Cd, and Hg, were synthesis and characterized by the mass and 1 HNMR spectrometry for ligand Schiff base, the fourier-transform infrared spectroscop (FTIR), UV- visible and the flame atomic absorption (AA) spectrum, the CHN analysis, and the chlorine content, in addition to measuring the magnetic sensitivity of the complexes. All the complexes had octahedral geometry. The bioactivity activity for compounds against; Rhizopodium, Staphylococcus aureus, and Escherichia coli showed different efficacy towards these microorganisms
The galvanic corrosion of the (Cu - Fe), (Cu - Zn) and (Fe - Zn) couples have been investigated in 3.5% NaCl solution, 40ºC, different velocities (Re = 5000, 10000 and 15000) and different area ratio’s of cathode to anode (AR= 0.5,1 and 2), by using commercial metal pipe (cylindrical tube).The Zero Resistance Ammeter has been used to measure the galvanic current (Ig) and galvanic potential (Eg) with time. The galvanic current density increases with increasing velocity (Re) and the area ratio (AR). The galvanic potential (Eg) is shifted to less negative with increasing velocity (Re) and the area ratio (AR). A statistical relations for the galvanic current density and galvanic potential as a function of (Re). and the area ratio had been
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