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Narzullaev Akmal Khollinorovich, Post-graduate student of Tashkent Scientific Research Institute of Chemical Technology E-mail: akmal.narzullayev.90@mail.ru, Beknazarov Khasan Soiibnazarovich, Doctor of engineering, Head Scientist of Tashkent Scientific Research Institute of Chemical Technology
Djalilov Abdulakhat Turapovich, Doctor of chemistry, Academician of the Academy of Sciences of Uzbekistan, Tashkent Scientific Research Institute of Chemical Technology,
EVALUATION OF INHIBITING PROPERTIES OF IC-DAlR-1 CORROSION INHIBITOR IN AQUEOUS AND SALINE MEDIA
Abstract. The article demonstrates environmental safety and efficiency of the use of developed inhibitors in IC-DAlR-1 systems in aqueous and saline media of water supply and in circulating water, as well as in oil and gas chemical industries.
Keywords: corrosion inhibitors, diethanolamine, oleic acid, zinc adduct, metal corrosion, phosphoric acid, nitrogen/phosphorus-containing inhibitors, amine groups.
Introduction. The inhibitors used are mainly protective properties, is a long-chain hydrocarbon
based on chemically pure reagents, which, of course, have an impact on the output product price. The literature describes metal corrosion inhibitors in water, aqueous solutions of acids, alkalis, salts, as well as corrosion inhibitors in atmospheric conditions and in non-aqueous liquid media. In addition to practical recommendations and the results of numerous experimental studies, many literature sources give an overview of theoretical models of the inhibitors mechanism, and study their classification [1].
Given the above, the aim of this article is to obtain new highly efficient, highly molecular corrosion inhibitors containing phosphate and amine groups and study the process of corrosion inhibition. In general, given that the expensive corrosion inhibitors are now fully imported, it seems appropriate to study the development and use of new oligomeric corrosion inhibitors [2].
Phosphorus/nitrogen-containing compounds showed by their protective properties that the most significant molecular fragment, determining their
radical, located at nitrogen donor atoms of the amino group or phosphorus of the phosphoryl group [3].
Experiment.
In this article, oligomeric corrosion inhibitors synthesized on the basis of diethanolamine, oleic acid and zinc adduct IC-DAlR-1 were studied.
The reaction was carried out in a 500 ml flask equipped with a reflux condenser for 9 hours at a temperature of 150-200 0C.
Corrosion inhibitor is used in tower cooling systems. One of the most effective corrosion inhibitors in water systems is IC-DAlR-1 inhibitor.
The protection degree of corrosion inhibitors was calculated by the formula
^ - V,
Z =
V
ko
V - is the corrosion rate of samples in non-inhibited medium, g*m-2 h
V - is the corrosion rate of samples in inhibited medium, g*m-2 h
EVALUATION OF INHIBITING PROPERTIES OF IC-DAlR-1 CORROSION INHIBITOR IN AQUEOUS AND SALINE MEDIA
K
IC-DAlR-1 and Puro-tech 1011 the corrosion rate (mass), is determined by the following formula:
g 0 — g 1
K„„„ =:
S-T
g0 - is the sample weight in the initial state; g1 - is the sample weight after reaction; S - is the surface under study; T - is the testing time. IC-DAlR-1
9.6281 - 9.6109 , 2,
K™*i - ^ = 0.8025 g 1 m2h
0.000893 • 24 Puro-tech 1011 K 8.0124 - 7.9680
= 2.0479 g / m2h
0.000882 • 24 Weight corrosion index is recalculated on a depth index according to the formula
p=8.76. Kman
Y
Where P - is the corrosion depth index; K - is the weight index of corrosion rate.
Mass c
Y - is the density of metal IC-DAlR-1
P = 8.76 • °.8025fi = 0.00000088 mm / g
7.91 40 Puro-tech 1011
P2 = 8.76 • 2'0479
= 0.00000226 mm / g
7.91 -10
The traditional method for graphic processing of polymerization curves to determine the corrosion rate is the extrapolation in semi-logarithmic coordinates of straight-line portions of cathodic and anodic branches
Table 1.- Protective properties of the oligomeric corrosion inhibitor in aqueous and saline media at 30 °C for 200 hours
before their mutual intersection. However, despite the obvious simplicity of the method, its practical use is often associated with a number of complications. The tangent construction itself is quite subjective, and a more reliable extrapolation requires an additional precise definition of corrosion potential [4; 5].
Results and discussion. Analysis of the studies has shown that the change in corrosion rate and the inhibitor efficiency depends on the inhibitor concentration. Table 1 shows the efficiency of a corrosion inhibitor in aqueous media.
Experimental evidence to study the corrosion rate of steel plates in IC-DAlR-1 aqueous dispersion, both with and without additives, showed that when the concentration changes, the steady-state electrode potential is shifted to a positive region due to the formation of corrosion protection of a barrier type. This effect is greatly enhanced along with an increase in the concentration ofan oligomer inhibitor in aqueous dispersion.
It should be also noted that the character of the inhibitor absorption onto the electrode surface, its efficacy, as well as the belonging of inhibitors to the cathodic and anodic types depend not only on its character, but also to a large extent on the medium potential. Judging by the steady-state potential, when IC-DAlR-1 is added, the protection degree is significantly increased. Moreover, more effective corrosion protection is provided when there is a 0.2% IC-DAlR-1 solution, the protective coefficient of which passes through a maximum.
Sample name With concentration% Medium Sample weight loss m, - m2 Protection degree, Z%
1 2 3 4 5
dis Watery - - - -
IC-DAlR-1 0.2 Aqueous 0.0015 96.25
IC-DAlR-1 0.05 Aqueous 0.002 95
IC-DAlR-1 0.001 Aqueous 0.0023 94.25
Puro-tech 1011 0.2 Aqueous 0.0018 95.5
Puro-tech 1011 0.05 Aqueous 0.0021 94.7
1 2 3 4 5
Puro-tech 1011 0.001 Aqueous 0.0025 93.75
IC-DAlR-1 0.2 NaCl 3% 0.004 90
IC-DAlR-1 0.05 NaCl 3% 0.0054 86.5
IC-DAlR-1 0.001 NaCl 3% 0.0057 85.75
Puro-tech 1011 0.2 NaCl 3% 0.0049 87.7
Puro-tech 1011 0.05 NaCl 3% 0.006 85
Puro-tech 1011 0.001 NaCl 3% 0.0068 83
The mechanism of this oligomeric corrosion inhibitor is mainly determined by the transition of the surface-protected metal to a stable surface film-type state involving particles of fine additives. However, the inhibitors effect in this case is more complex than in film-formation, and is also associated with the nature of ion adsorption of the surface-active agent [6]. For example, if the electrode surface is positively charged relative to the solution, the oligomer inhibitor, which is anion, will be adsorbed onto, ifthe inhibitor surface is negatively charged - undissociated molecules.
Therefore, the transition to another condition ofthe process changes the coatings structure or the steady-state potential of metal. By changing the solution composition or applying external polarization, the nature of absorption and, consequently, the nature and effec-
containing oligomers may change. In general, the oligomeric corrosion inhibitors that were synthesized by us have a sufficiently high efficiency of inhibitory effect.
Conclusion. Inhibitors with substituents near the phosphoryl group are more effective in corrosion protection. The protective effect of nitrogen/ phosphorus-containing inhibitors is due to the formation of tightly packed films on the surface of steel.
The protective effect of multi-component polymer-type inhibitors based on industrial waste and local raw materials, exceeding that of imported inhibitors up to 5 percent, has been achieved;
The environmental safety of the use of developed inhibitors in water supply systems and circulating water, as well as in oil and gas chemical industries has been shown, their efficiency of 95.15% has been determined.
tiveness of inhibitors based on phosphorus/nitrogen-
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