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It is shown from the presented experimental data that tration is 20 mg/l from the economical and techno-the best results were obtained at concentration 50 mg/l logical presentations. These inhibitors by the value of investigated inhibitors MPU and MPHMD. of the protective effect didn't yield to analogues and The obtained results also have shown that at can be used in oil industry for the anticorrosion prosmall concentrations MPU and MPHMD have dis- tection of equipment of boring wells and in some played inhibition properties. Their optimal concen- other fields.
References:
1. Kuznecov V. Y. Physic-chemical aspects of the corrosion inhibition of metals in water solutions//Successes of chemistry. 2004 № 1. T. 73. - P. 79-93.
2. Shpanko S. P., Grigorev V. P., Olexanov E. V., Anisimova V. A. Inhibitional action of benzymidazole derivatives at the acid corrosion of ferrum//Physic-chemistry of surface and the metals protection - M: 2010, T 46, № 2. - P. 208-213.
3. Semenova I. V., Florianovich G. M., Horoshilov A. V. Corrosion and the protection from corrosion - M: 2002. 336 p.
4. Eshmamatova N. B. Protection of carbon steel from corrosion by high-effective oligomeric inhibitors//51-th International Scientific conference MHCK-2013. - Novosibirsk. 2013. - P. 59.
Ergashev Dilmurod Adiljonovich, research assistant of the Institute of General and Inorganic Chemistry the Academy of Sciences of Uzbekistan E- mail: [email protected] Askarova Mamura Komilovna, candidate of chemical sciences (Ph. D. in Chemistry), senior staff scientist of the Institute of General and Inorganic Chemistry the Academy of Sciences of Uzbekistan E-mail: [email protected] Saiydiaxral Tuxtaev, the head of Defoliant laboratory, doctor of technical sciences, professor, academician, honored inventor and innovator of Uzbekistan, the Institute of General and Inorganic Chemistry the Academy
of Sciences of Uzbekistan E-mail: [email protected].
Investigation of the mutual effect of the components in systems substantiating the process of obtaining a new defoliant
Abstract: Heterogenic phase equilibrium in aqueous systems composed of calcium and magnesium chlorates were investigated. It was found that the system including calcium and magnesium chlorates belongs to the simple eutonical type, where salting-out effect of the components to each other were observed. Change dependence of physi-cochemical properties of the solutions in the system, including chlorates and chlorides of calcium and magnesium and carbamide, depending on the composition of components has been studied. "Composition-property" diagram has been constructed for this system.
Keywords: defoliant, polythermal, temperature crystallizations, solubility, diagram, calcium chlorate, magnesium chlorate, carbamide, thermogravimetric, roentgenophasic.
Introduction ment — defoliation by chemical preparations called
In obtaining early and rich crop of raw cotton with defoliants. By chemical effect on cotton plant for the
high technological properties exceptionally an impor- purpose of removal of leaves it is necessary high effective
tant role plays timely conduction of agrotechnical treat- defoliants that can give more than 80% phylloptosis of
cotton for one treatment at low norms of consumption, acting mildly on plants and consequently not to affect adversely on crop, oil content of seeds, quality of lint cotton and not to litter it.
Existing assortment of recommended defoliants do not completely comply current demand put forth by agriculture and public health services with chemical weed and pest killers. Chlorate containing defoliants in terms of production and application are low toxic and cheap.
Manufactured in Uzbekistan and widely used in agriculture magnesium chlorate defoliant contains 36% of the active substance in its composition [1]. Magnesium chloride (bischofite) is used as a raw material for the production of magnesium chlorate, 50% of which is imported for the currency from abroad. It increases the cost rising of the defoliant.
In this regard, production of chlorate containing preparations based on local raw materials and increasing their efficiency, and also reducing the "rigidity" effect on cotton and development on their of more effective, fully acting defoliants is an actual problem in cotton growing.
Currently, a new calcium-magnesium chlorate defoliant based on local raw material dolomite is being developed, decomposing it by hydrochloric acid and subsequent conversion of decomposed products by sodium chlorate [2].
It is known that a combination of chlorate containing defoliants with mineral fertilizers leads to increase of defoliating activity and reduce "rigidity" of their effects on plants [3,4]. To improve the defoliating activity of a new calcium-magnesium chlorate defoliant by introducing carbamide into its composition and development of more efficient cotton defoliant on their bases it is necessary to gain information about the mutual influence of the initial components in the system: Ca (Cl03)2-Mg (Cl03)2-H2 O and {[40.03%!Ca (Cl03)2+Mg (Cl03)2] + 7.45596! [CaCl2+MgCl2]+52.52%H2O} — CO (NH2)2.
Objects and methods of research
The objects of research are calcium and magnesium chlorates and carbamide. Dihydrate calcium chlorate Ca (ClO3)2-2H2O obtained as described in [5]. Magnesium chlorate was synthesized by the method described in
[6]. Carbamide was used grade "clean for analysis" which was twice recrystallization from water solution. Visual-polythermic method was used during the study
[7]. Generally known techniques of analytical chemistry was used in quantitative chemical analysis, in particular, chlorate and chloride ions were determined by volumet-ric-permanganometric and argentometric methods [9;
10], calcium and magnesium were determined on the atomic-absorption spectrophotometer [10].
The content of elemental nitrogen, carbon and hydrogen were determined according to [11]. Analytical data were used to determine the composition of solid phase by Schreinemakers'method [12].
The solid phases were identified by various chemical and physico-chemical methods of analysis. Values of in-terplanar spacings were found from the reference book [13] according to the angle of reflection, and the intensity of the diffraction lines were evaluated by a hundred point scale. Thermal analysis of examining new phase was carried out on a Netzsch Simultaneous Analyzer STA 409 PG (Germany), with thermocouple K-type (Low RG Silver) and aluminium crucible.
Results and discussion
Mutual influence of the components in the system Ca (ClO3)2-Mg (ClO3)2-H2O was studied by visual polythermal method at a wide temperature and concentration range. Calcium chlorate-water and magnesium chlorate-water binary systems were previously studied. The data we obtained are agreed well with the literature [14; 15]. The solubility of the components in the system of Ca (ClO3)2-Mg (ClO^-^ O has been studied using ten internal sections. Sections I-IV has been conducted by magnesium chlorate-water side to the top of calcium chlorate, and V-X from calcium chlorate-water side to magnesium chlorate pole. Based on solubility data of binary systems and internal sections solubility polythermal diagram of Ca (ClO3)2-Mg (ClO3)2-H2O have been constructed from the eutectic freezing point (-61.7 °C) till 60.0 °C (Fig. 1).
Field of crystallization of solid phases of ice, hexa-, tetra- and dihydrated calcium chlorates as well as sixteen-, twelve-, hexa- and tetra hydrated magnesium chlorates have been demarcated on polythermal solubility diagram of the studied system. Fields converge in four nodal points of invariant ternary system (Table 1).
On polythermal diagram of state isothermal curves of solubility were plotted at every 10 °C. Projections of polythermal curves of solubility have been constructed on corresponding side water systems. It is seen that the given data in the studied system formation of new chemical compounds have not been taken place on the basis of initial components. The system refers to a simple eu-tonical type.
Analysis of solubility polythermal diagrams of Ca (ClO3)2-Mg (ClO3)2-H2O indicates that the components of the system have a mutual salting-out effect to each other.
Figure 1. Solubility diagram of the system of Ca (ClO3)2-Mg (ClO3)2-H2O Table 1. - Double and triple nodal points of the system of Ca (ClO3)2-Mg (ClO3)2-H2O
Composition of liquid phase, % Solid phase
Ca(ClO3)2 Mg(Cl°3)2 H2 0 t , °C crys'
1 2 3 4 5
- 36.9 63.1 -52,0 Ice + Mg (ClO,)2-16 H2 O
6.4 35.3 58.7 -61.7 Ice + Ca (ClO,)2-6 H2 O + Mg (ClO,)2-16 H2 O
9.3 27.3 63.4 -55.2 Ice + Ca (ClO,)^6 H2 O
16.4 18.3 65.3 -48.4 Same
18.6 16.7 64.7 -47.7 —
26.5 11.6 61.9 -44.2 —
36.6 6.4 57.0 -42.2 —
37.8 5.7 56.5 -41.7 —
46.1 — 53.8 -40.3 —
- 42.0 58.0 -21.7 Mg (ClO,)2-16 H2 O + Mg (ClO,)2-12 H2 O
4.8 41.0 54.2 -35.0 Mg (ClOA-16 H, O + Mg (ClOj/12 H, O + Ca (ClOj,-6 H O
5.0 38.0 57.0 -41.8 Mg (ClO,)2-16 H2 O + Ca (ClO,)^6 H2 O
- 45.4 54.6 -7.5 Mg (ClOj/16 H O + Ca (ClOj/6 H O
3.9 45.0 51.1 -15.6 Mg (ClO,)2^12 H2 O + Mg (ClO,)^6 H2 O + Ca (ClO,)^6 H2 O
55.0 - 45.0 -27.2 Ca (ClO,)24 H2 O + Ca (ClO,)2-6 H2 O
50.5 5.0 44.5 -27.4 Same
44.0 11.8 44.2 -27.8 —
36.4 19.7 43.9 -28.0 —
27.5 29.8 42.7 -28.2 —
14.6 52.0 33.4 -29.4 —
62.0 - 38.0 -6.8 Ca (ClO,)2-2 H2 O + Ca (ClO,)2-4 H2 O
57.5 4.7 37.8 -7.0 Same
1 2 3 4 5
52.0 10.2 37.8 -7.3 Same
46.2 16.7 37.1 -7.6 —
44.0 19.4 36.6 -7.9 —
39.8 24.8 35.4 -8.1 —
28.3 43.0 28.7 -8.9 —
- 63.3 36.7 34.2 Mg (ClOj/6 H, O + Mg (ClOj/4 H, O
3.2 62.8 34.4 30.0 Mg (ClO,)2-6 H2 O + Mg (ClO,)2-4 H2 O + Ca (ClO,)^6 H2 O
The aim subsequent studies is investigation of novel more effective preparation, which has high defolationing activity and "soft" action on cotton based on calcium-magnesium defoliant having the following composition {[40,03%XCa (Cl03)2+Mg (Cl03)2]+ 7,45%X [CaCl2+MgCl2]+52,52%H2O} and carbamide.
It is necessary to know the behavior of the physical and chemical properties of the solutions of {[40.03%XCa (Cl03)2+Mg (ClO3)2]+7.45%X [Caa2+MgCl2]+52.52%H2O}-CO (NH2)2 for the physico-chemical validation and recommendations for the process of obtaining of a new defoliant.
In this connection, to ascertain the influence of the components on the physico-chemical properties of the solutions of the above indicated system, the dependence
T,°C pH
of the crystallization temperature change, pH, refractive index, viscosity and density of the fluids from the composition have been determined. On the basis of the obtained data on physico-chemical properties of the solutions "structure-property" diagram of the system has been constructed (Table 2, Fig. 2). "Composition-temperature of crystallization" of the system is characterized by the presence of two branches of crystallization with a clear break in the solubility curve according to the data chart (Fig. 2, Curve 1). Crystallization of {[84.3%!Ca (ClO3)2+ Mg (ClO3)2]+ [^^yoXCaC^+MgClJ} extends to 14.55% ofcarbamide at -4.3 °C. At this point, the crystallization of {[84.3%!Ca (ClO3)2+Mg (ClO3)2] + [15.69%XCaCl2+MgCl2]} and the compound of Ca (C103)2-Mg (C103)2.8 CO (NH2)2-4H20 take place.
d, g/sm3t), mm2/s i®20
30 - 10- -1,71 -1,4430
-11,0
/ 3
40 - 9- -1,66 -1,4423
-10,0
30 - 8- f 4 / -1,61 -9,0 -1,4400
20 - 7- -1,36 -1,43 7 3
-8,0
j 1
10 - 6- „ J Jf -1,31 -1,43 3 0
-7,0
s 4
o- 5- / 3 1 -1,46 -6,0 -1,43 2 3
/ 2
-10- 4- -1,41 -1,43 0 0
1 1 1
0 3
[40,03%XCa,Mg (C103)2+ 7.45%T Ca.MgCb I 52,520/qH2O]
CO(NH2)2
Figure 6. "Composition-property" graph of the system {[40.03%!Ca (ClO3)2+Mg (ClO3)J+7.45%X [CaCl6+MgCl6]+52.52%H6O}-CO (NH2)2 1-crystallization temperature, 2-pH, 3-refractive index, 4-viscosity, 5-density
Increasing the concentration of carbamide by more than 14.55% causes crystallization of the compound of Ca (Cl03)2-Mg (Cl03)2-8 CO (NH2)24H2O. Analysis of the diagram of "composition-pH" (Fig.2, curve 2) shows that the pH of the solutions gradually increases by addition of carbamide. In the double point the pH of the solution is 4.71. Further, with increasing the concentration of carbamide over 14.55%, i. e. in the crystallization point of the compound, the pH of the solutions increase sharply from 4.71 to 5.30.
"Composition-property" graph is also characterized by the presence of two branches of crystallization, with fracture index on the curve (Fig. 2, curve 3). Viscosity values of solutions of the studied system are gradually increased from 6.69 mm 2/s and reach a value
of 8.75 mm 2/s at a double point, i. e. at the content of 14.55% of carbamide (Fig. 2, curve 4). With increasing the concentration of carbamide the viscosity of the newly formed solutions rises and reaches 9.75 mm 2/s, due to the change in the field of crystallization of the system.
Analysis of "composition-density" graph of the system (Fig. 2, curve 5) shows that with increasing the concentration of carbamide the densities of the newly formed solutions decrease. There is also a fracture on the curve 5 of the "composition-property" diagram. The crystallization branches of the sum of calcium and magnesium chlorates, and calcium and magnesium chlorides correspond to the densities of solutions of 1.5110*1.4715 g/cm3 (Table 2).
Table 2. - The relationship of the crystallization temperature change, refractive index, pH, viscosity, density of solutions in the system of {[40.03%ICa (Cl03)2+Mg (Cl03)2]+7.45%I [CaCl2+MgCl2]+52.52%H2O}-CO (NH2)2
№ Content of components,% t , crys' °C mm 2/s d, g/sm 3 pH nD20
{[40.03%XCa (Cl03)2+Mg (Cl03)2] + +7.45%X [CaCl2+MgClJ+52.52%H2O| CO (NHA
1 100 - 10 6.69 1.5110 4.01 1.4300
2 98.86 1.14 9.4 6.83 1.5095 4.17 1.4320
3 97.1 2.90 8.2 7.08 1.5060 4.25 1.4337
4 95.8 4.20 7.0 7.25 1.5020 4.30 1.4350
5 93.66 6.34 5.2 7.45 1.4950 4.32 1.4366
6 91.5 8.50 3.0 7.89 1.4875 4.37 1.4383
7 90.0 10.0 1.4 8.14 1.4830 4.45 1.4393
8 88.66 11.34 -0.2 8.29 1.4800 4.50 1.4401
9 86.8 13.20 -2.4 8.56 1.4750 4.60 1.4412
10 85.45 14.55 -4.3 8.75 1.4715 4.71 1.4419
11 84.43 15.57 13.5 9.20 1.4635 4.94 1.4430
12 82.85 17.15 22.7 9.50 1.4590 5.12 1.4435
13 81.43 18.57 28.0 9.75 1.4550 5.30 1.4440
Density values ofthe solutions of1.4715*1.4550 g/cm 3 correspond to the crystallization branch of the compound of Ca (ClO3)2-Mg (ClO3)2-8CO (NH2)2-4H2O.
Compounds formed in the studied system were isolated in the crystalline form and identified by chemical, X-ray and thermal methods of analyses.
According to chemical analysis, the masses of the compounds found were%: Ca (Cl03)2 = 21.55; Mg (Cl03)2 = 20.0; CO (NH2)2 = 50.7; H2O = 7.68.
Formation of compound Ca (Cl03)2-Mg (Cl03)2-8 CO (NH2)2-4H2O was confirmed by X-ray diffraction data. Comparison of diffraction lines and corresponding values of the interplanar spacings of the compound and its components showed that the compound is individual, with its inherent structure of the crystal lattice (Fig.3).
TG-DSC investigation of Ca (ClO3)2-Mg (ClO3)2-8 CO (NH2)2-4H2O at the temperature range of 20-550 °C is characterized by the presence of an en-dothermic effect at 144.1 °C and two exothermic effects at 248.0 and 264.7 °C.
The endothermic effect at 144.1 °C corresponds to the removal ofwater, the weight loss at which is 7.86% on the TG derivatograph. Exoeffect at 248.0 °C corresponds to the decomposition of the compound, the weight loss at which is 39.70% on the TG curve.
In the next exothermic effect at 264.7 °C further decomposition of the compound occurs and the weight loss is TG = 76.13%. At the temperature range of 2050 °C the total weight loss was 90% (Fig. 4).
Figure 3. X-ray diffraction of [Ca (ClO3)2-Mg (ClO3)2-8CO (NH2)-4H2O]
Figure 4. TG-DSC of [Ca (ClO3)2 The isolated compound of the Ca (ClO3)2-Mg (ClO3)2-8CO (NH2)2-4 H2 O is a white crystalline substance. Solubility in water at 0, 10 and 20 °C are 54.4%, 59.0 and 62.8 wt.%, respectively. The compound is slightly soluble in alcohol and acetic acid, and poorly soluble in acetone and benzene.
It is necessary to dissolve carbamide in the solution of calcium-magnesium chlorate defoliant in a mass ratio of 1.0:0.1 to obtain an effective "soft" acting preparation, having defoliating activity based on the results of the "composition-property" study of the above mentioned system and conducted agrochemical tests of the defoliant components. This forms a defoliant so-
Mg (ClO3)2-8CO (NH2)2-4H2O]
lution, with good physicochemical properties, having a temperature of crystallization of 1.4 °C, viscosity is 8.14 mm 2/s, density is 1.4830 g/cm 3, and the pH is 4.45.
Conclusions
Thus, the mutual influence of the components in the systems Ca (ClO3)2-Mg (ClO3)2-H2 O; Ca (ClO3)2-CO (NH2)2-H2O at 25 and 50 °C, {[40.03%ICa (ClO3)2+Mg (ClO3)2]+ 7.45%X [CaCl2+MgCl2]+52.52%H2O}-CO (NH2)2 have been studied.
The results of the studied systems were the basis for the recommendation of the composition of the new liquid chlorate containing preparation for defoliation.
References:
1. List of chemical and biological pest control, plant diseases and weeds, defoliants and plant growth regulators permitted for use in agriculture of the Republic of Uzbekistan for 2002-2006, Tashkent, 2002. P. 96, (in Russian).
2. Hamrakulov Z. A., Askarova M. K., Tukhtaev S., Preparation of calcium-magnesium chlorate defoliant from dolomite, Journal of Chemical Technology and Metallurgy, Volume 50, Issue 1, 2015. P. 65-70.
3. Tukhtaev S., Kucharov Kh., and Yusupov A.Kh. Synthesis of defoliant on the basis of calcium chlorate-chloride and carbamide. XIV All-Union Scientific and Technical Conference on Technology of inorganic substances and fertilizers/Abstracts, Part III. Lvov, 1988, P. 50, (in Russian).
4. Nabiyev M. N., Tukhtaev S., Shammasov R. E., Musayev N. Y., and Burhanov Sh. Investigation of physicochemical properties of defoliants on the basis of magnesium chlorate and components of fertilizers (such as UDM).//Uzb. chemical. J., 1980, 3, P. 48-51, (in Russian).
5. A. S. 1143691 USSR. A method for producing calcium chlorate-chloride defoliant/M. N. Nabiyev, R. Shammasov, S. Tukhtaev, Kh. Kucharov et al. (USSR) - № 3620951/23-26; reported on 23.05.83.; published on 07.03.85//Discovery, invention. - 1985. - № 9, P. 84, (in Russian).
6. Martynov Y. M., Matveev M. A., Yakimenko L. M., Furman A. A. The technology of production and application of magnesium chlorate defoliants.//Chemical industry. 1958, 7, pp. 420-423, (in Russian).
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8. State standard 12257-77, Sodium chlorate, Moscow, Standard agency's publishing house, 1987, P. 19, (in Russian).
9. Dorokhova E. N., Prokhorova G. V. Analytical chemistry: Physical-chemical methods of analysis, Moscow, 1991, (in Russian).
10. Khavezov I., Salev D., Atomic Absorption Analysis, Sofia, 1980, (in Bulgarian).
11. Klimova V. A. Basic micro methods of analysis of organic compounds. Moscow, Chemistry, 1975, P. 224 (in Russian).
12. Anosov V. Y. Descriptive geometry in application to chemical diagrams of the ternary and quaternary systems. Moscow-Leningrad: Publishing House of the USSR Academy of Sciences, 1949, P. 176, (in Russian).
13. Giller Y. L. Tables of interplanar spacings. V.2., M.: Nedra, 1966. - P. 330.
14. Kirgintsev A. N. et al. The solubility of inorganic substances in the water. - Leningrad, Chemistry, 1972, P. 248, (in Russian).
15. Tukhtaev S. Shammasov R. E., KucharovKh. Solubility polyterm of magnesium chlorate - water system//Dokl. AN Uz SSR, 1984, 1, P. 31-32 (in Russian).
Urinov Ulugbek Komiljonovich, Tashkent Institute of Chemical Technology,
the assistant Maksumova Oytura Sitdikovna, Tashkent Institute of Chemical Technology, Doktor of Chemistry, Professor E-mail: [email protected] Abdumalikova Xusnora Bahodir kizi Tashkent Chemical Technological Institute, Bachelor-student
About the reaction of urea with epichlorohydrin
Abstract: In the paper the reaction of urea with epichlorhydrin in the absence and presence of acid catalysts has
been studied. It has been established that in absence of the catalyst the reaction proceeds on amides with the formation of chlorohydrin of urea, and in the presence of acid catalysts there is a formation of cyclic ketals. Keywords: urea, epichlorohydrin, synthesis, structure.
