Pub Date : 2020-09-08DOI: 10.6060/ivkkt.20206310.6240
I. Chetvertneva, O. Karimov, G. Teptereva, E. Movsumzade
The article proposes a method of increasing the amount of OH-phenolic functional groups in the composition of a macromolecule lignosulphonate, a sulfo-derivative natural lignin polymer, tested under laboratory conditions by step-by-step chemical treatment of the lignosulphonate matrix with a solution of a bromine derivative, then with a solution of neutral sodium sulfite. This makes it possible to solve the problem characteristic of modern lignosulphonates of neutral sulfite production method, which have low values of tannidicity index: content of OH-phenolic groups, quantitative content of which forms inhibitory (tanning) capacity of lignosulphonates. The proposed procedure involves carrying out said demethylation reaction with cleavage of methyl group contained in phenylpropane unit of lignosulfonate. Pyrocatechin groups are formed and methanesulfonic acid molecule is cleaved off. The obtained product was analyzed by UV spectroscopy and the increase in optical density in the area of absorption of 280 nm characteristic of OH-phenolic functional groups was shown, which is the basis for the appearance of pyrocatechin structures in the phenylpropane unit of lignosulfonate. Proposed method allows increasing quantitative content of OH-phenolic groups in macromolecule composition from 1.7% of initial to 6.5%. The obtained results are correlated with the data on determination of tannidicity index - one of objective characteristics of inhibitory (tanning) capacity of lignosulfnates, which is 32%, compared to similar characteristic of undemethylated neutral lignosulfonate, where the value did not exceed 21%. The data show that demethylation of the lignosulphonate matrix is possible by converting modern inactive neutral lignosulphonates from the low-demand waste category of the pulp and paper industry to a promising raw material component.
{"title":"POSSIBILITIES OF IMPROVING QUALITY CHARACTERISTICS OF INACTIVE NEUTRAL LIGNOSULFONATES","authors":"I. Chetvertneva, O. Karimov, G. Teptereva, E. Movsumzade","doi":"10.6060/ivkkt.20206310.6240","DOIUrl":"https://doi.org/10.6060/ivkkt.20206310.6240","url":null,"abstract":"The article proposes a method of increasing the amount of OH-phenolic functional groups in the composition of a macromolecule lignosulphonate, a sulfo-derivative natural lignin polymer, tested under laboratory conditions by step-by-step chemical treatment of the lignosulphonate matrix with a solution of a bromine derivative, then with a solution of neutral sodium sulfite. This makes it possible to solve the problem characteristic of modern lignosulphonates of neutral sulfite production method, which have low values of tannidicity index: content of OH-phenolic groups, quantitative content of which forms inhibitory (tanning) capacity of lignosulphonates. The proposed procedure involves carrying out said demethylation reaction with cleavage of methyl group contained in phenylpropane unit of lignosulfonate. Pyrocatechin groups are formed and methanesulfonic acid molecule is cleaved off. The obtained product was analyzed by UV spectroscopy and the increase in optical density in the area of absorption of 280 nm characteristic of OH-phenolic functional groups was shown, which is the basis for the appearance of pyrocatechin structures in the phenylpropane unit of lignosulfonate. Proposed method allows increasing quantitative content of OH-phenolic groups in macromolecule composition from 1.7% of initial to 6.5%. The obtained results are correlated with the data on determination of tannidicity index - one of objective characteristics of inhibitory (tanning) capacity of lignosulfnates, which is 32%, compared to similar characteristic of undemethylated neutral lignosulfonate, where the value did not exceed 21%. The data show that demethylation of the lignosulphonate matrix is possible by converting modern inactive neutral lignosulphonates from the low-demand waste category of the pulp and paper industry to a promising raw material component.","PeriodicalId":14640,"journal":{"name":"IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85628101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-08DOI: 10.6060/ivkkt.20206310.6285
Natalia N. Kuranova, D. Kabirov, O. V. Kashina, T. Usacheva
The distribution coefficients of quercetin (QCT) in water-dimethylsulfoxide solvents with a content of dimethylsulfoxide from 0.0 to 0.5 mol. fr. were determined by the method of interfacial distribution of the substance between two immiscible phases: aqueous or water-dimethylsulfoxide solution and n-hexane at 298.2 K. The distribution coefficients are less than one, which indicates a better solvation of quercetin in water and a water-dimethylsulfoxide solvent than in hexane. Changes in the distribution coefficients of quercetin are not correlated with a gradual increase in the content of dimethylsulfoxide (DMSO) in the solvent. Using the obtained values of the distribution coefficients, we calculated the changes in the Gibbs energy of re-solvation of quercetin in water-dimethylsulfoxide solvents. The dependence of the Gibbs energy of QCT re-solvation on the solvent composition has an extreme form with a minimum in the range of DMSO concentrations corresponding to 0.3 mol. fr. A comparative analysis of the effect of a water-dimethylsulfoxide solvent on the change in Gibbs energy of re-solvation of quercetin, nicotinamide and nicotinic acid was carried out. In the case of both nicotinamide and nicotinic acid, an extreme change is observed in the Gibbs energy of re-solvation of particles with a maximum in the region with a low content of non-aqueous component XDMSO ≈ 0.1 mol. fr. The main contribution to the weakening of the solvation of nicotinamide and nicotinic acid is due to the enthalpy component, and with increasing concentration of dimethylsulfoxide there is an increase in the contribution of entropy to the change in the Gibbs energy transfer. An extreme change in the Gibbs energy transfer of quercetin suggests that the minimum on the dependence ∆trGº(QCT) = F(χDMSO) is also a consequence of a change in the prevailing thermodynamic factor in the solvate state of quercetin.
{"title":"THERMODYNAMICS OF QUERCETIN SOLVATION IN WATER-DIMETHYLSULFOXIDE SOLVENT","authors":"Natalia N. Kuranova, D. Kabirov, O. V. Kashina, T. Usacheva","doi":"10.6060/ivkkt.20206310.6285","DOIUrl":"https://doi.org/10.6060/ivkkt.20206310.6285","url":null,"abstract":"The distribution coefficients of quercetin (QCT) in water-dimethylsulfoxide solvents with a content of dimethylsulfoxide from 0.0 to 0.5 mol. fr. were determined by the method of interfacial distribution of the substance between two immiscible phases: aqueous or water-dimethylsulfoxide solution and n-hexane at 298.2 K. The distribution coefficients are less than one, which indicates a better solvation of quercetin in water and a water-dimethylsulfoxide solvent than in hexane. Changes in the distribution coefficients of quercetin are not correlated with a gradual increase in the content of dimethylsulfoxide (DMSO) in the solvent. Using the obtained values of the distribution coefficients, we calculated the changes in the Gibbs energy of re-solvation of quercetin in water-dimethylsulfoxide solvents. The dependence of the Gibbs energy of QCT re-solvation on the solvent composition has an extreme form with a minimum in the range of DMSO concentrations corresponding to 0.3 mol. fr. A comparative analysis of the effect of a water-dimethylsulfoxide solvent on the change in Gibbs energy of re-solvation of quercetin, nicotinamide and nicotinic acid was carried out. In the case of both nicotinamide and nicotinic acid, an extreme change is observed in the Gibbs energy of re-solvation of particles with a maximum in the region with a low content of non-aqueous component XDMSO ≈ 0.1 mol. fr. The main contribution to the weakening of the solvation of nicotinamide and nicotinic acid is due to the enthalpy component, and with increasing concentration of dimethylsulfoxide there is an increase in the contribution of entropy to the change in the Gibbs energy transfer. An extreme change in the Gibbs energy transfer of quercetin suggests that the minimum on the dependence ∆trGº(QCT) = F(χDMSO) is also a consequence of a change in the prevailing thermodynamic factor in the solvate state of quercetin.","PeriodicalId":14640,"journal":{"name":"IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82482096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-13DOI: 10.6060/ivkkt.20206306.6181
Y. Gurov, Evgeny О. Zemlianskii, A. Mozyrev, S. G. Agaev
In the proposed work, the experimental data on the processes of crystallization and different nature waxy hydrocarbons recrystallization in hydrocarbon solvents have been compared. T-1 technical paraffin (GOST 23683-89) with the melting point of 54 °С and ceresin-80 (GOST 2488-79) with the dropping temperature of 80 °C have been used. РТ-1 kerosene (GOST 10227-86) and de-waxed oil of fraction 420-490 °С have been used as hydrocarbon solvents. The experimental data on crystallization and recrystallization processes of paraffin wax with a melting temperature of 54 ºC and ceresin with a dropping temperature of 80 °C in kerosene and dewaxed oil are presented in this paper. It is shown that chemical structure has the main influence on the processes of crystallization and recrystallization of solid petroleum hydrocarbons. An exceedance of solid hydrocarbons solution temperatures tр above their cloud points tп has been observed which is explained by hysteretic processes. The temperature difference Δt = tр- tп depends on the solid hydrocarbons nature and their content in solvents. Wax solutions in kerosene have higher values Δt relative to ceresin solutions in kerosene, which can be explained by the difference in chemical structure of solid hydrocarbons. With the increase in solid hydrocarbons content in their solvents due to the differences in solid hydrocarbons diffusion rate, Δt decreases. The discovered regularities of solid hydrocarbons crystallization and recrystallization should be taken into account in the processes of paraffin oil production, transportation and processing.
{"title":"PARAMETERS CRYSTALLIZATION PROCESSES AND SOLID PETROLEUM HYDROCARBONS DISSOLUTION","authors":"Y. Gurov, Evgeny О. Zemlianskii, A. Mozyrev, S. G. Agaev","doi":"10.6060/ivkkt.20206306.6181","DOIUrl":"https://doi.org/10.6060/ivkkt.20206306.6181","url":null,"abstract":"In the proposed work, the experimental data on the processes of crystallization and different nature waxy hydrocarbons recrystallization in hydrocarbon solvents have been compared. T-1 technical paraffin (GOST 23683-89) with the melting point of 54 °С and ceresin-80 (GOST 2488-79) with the dropping temperature of 80 °C have been used. РТ-1 kerosene (GOST 10227-86) and de-waxed oil of fraction 420-490 °С have been used as hydrocarbon solvents. The experimental data on crystallization and recrystallization processes of paraffin wax with a melting temperature of 54 ºC and ceresin with a dropping temperature of 80 °C in kerosene and dewaxed oil are presented in this paper. It is shown that chemical structure has the main influence on the processes of crystallization and recrystallization of solid petroleum hydrocarbons. An exceedance of solid hydrocarbons solution temperatures tр above their cloud points tп has been observed which is explained by hysteretic processes. The temperature difference Δt = tр- tп depends on the solid hydrocarbons nature and their content in solvents. Wax solutions in kerosene have higher values Δt relative to ceresin solutions in kerosene, which can be explained by the difference in chemical structure of solid hydrocarbons. With the increase in solid hydrocarbons content in their solvents due to the differences in solid hydrocarbons diffusion rate, Δt decreases. The discovered regularities of solid hydrocarbons crystallization and recrystallization should be taken into account in the processes of paraffin oil production, transportation and processing.","PeriodicalId":14640,"journal":{"name":"IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79021020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-17DOI: 10.6060/ivkkt.20206304.6128
R. Vakhitova, D. Saracheva, I. Kiyamov, L. Sabitov, V.Iv. Oleinik
This article describes the results of studies conducted by the authors to study the destruction processes of stable emulsion suspension sludge systems. Destruction processes are achieved by adding nanoparticles to demulsifying compositions. Currently, there is no universal composition of demulsifier that effectively destroys emulsions formed in oil sludges. To solve this problem, the authors conducted research on the creation of an effective demulsifier containing nanosized particles of fullerenes. The studies were carried out with dispersed oil-slurry emulsion-suspension systems, selected from open storage ponds of enterprises of JSC «Tatoilgaz» and JSC «TAIF-NK». For the destruction of the oil-containing system of the emulsion-suspension type, a composite mixture of complex action has been developed, which includes anionic wetting agents, nonionic surfactants, flotation reagents, detergents and alkaline buffer solutions that provide the required value of a constant indicator of the acid-base balance of the aqueous medium. A composite demulsifying mixture of complex action, which increases the effectiveness of the wetting washing action of surfactants, namely, the diphilic structure of the dispersed medium changes to hydrophilic, that is, the contacts of particles having a monophilic surface with the hydrocarbon phase of the emulsion medium are broken. Then the particles pass from the boundary of the phase separation into the water volume, thereby contributing to the destruction of the layers on the surface of emulsified water. The process of dehydration of petroleum products is intensified, the duration from 6 to 8 hours is reduced to from 3 to 4 hours. During the research, it was possible to intensify and increase the efficiency of the oil preparation process during its dehydration.
{"title":"DESTRUCTION OF STABLE EMULSIONS USING NANODISPERSED FULLERENES","authors":"R. Vakhitova, D. Saracheva, I. Kiyamov, L. Sabitov, V.Iv. Oleinik","doi":"10.6060/ivkkt.20206304.6128","DOIUrl":"https://doi.org/10.6060/ivkkt.20206304.6128","url":null,"abstract":"This article describes the results of studies conducted by the authors to study the destruction processes of stable emulsion suspension sludge systems. Destruction processes are achieved by adding nanoparticles to demulsifying compositions. Currently, there is no universal composition of demulsifier that effectively destroys emulsions formed in oil sludges. To solve this problem, the authors conducted research on the creation of an effective demulsifier containing nanosized particles of fullerenes. The studies were carried out with dispersed oil-slurry emulsion-suspension systems, selected from open storage ponds of enterprises of JSC «Tatoilgaz» and JSC «TAIF-NK». For the destruction of the oil-containing system of the emulsion-suspension type, a composite mixture of complex action has been developed, which includes anionic wetting agents, nonionic surfactants, flotation reagents, detergents and alkaline buffer solutions that provide the required value of a constant indicator of the acid-base balance of the aqueous medium. A composite demulsifying mixture of complex action, which increases the effectiveness of the wetting washing action of surfactants, namely, the diphilic structure of the dispersed medium changes to hydrophilic, that is, the contacts of particles having a monophilic surface with the hydrocarbon phase of the emulsion medium are broken. Then the particles pass from the boundary of the phase separation into the water volume, thereby contributing to the destruction of the layers on the surface of emulsified water. The process of dehydration of petroleum products is intensified, the duration from 6 to 8 hours is reduced to from 3 to 4 hours. During the research, it was possible to intensify and increase the efficiency of the oil preparation process during its dehydration.","PeriodicalId":14640,"journal":{"name":"IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85516016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-15DOI: 10.6060/ivkkt.20206305.6084
I. Khristoforova, A. Khristoforov
In this work, we report on phase equilibrium in systems «plasticizer mix - blowing agent». Dioctiphthalate, butylbenzylphthalate and dicresyl phosphate were used as plasticizer, and simple oligoesters (ethylene glycol, diethylene glycol, triethylene glycol) served as a blowing agent. We conducted an experiment and built triple phase diagrams. Diphenylcresylphosphate proved to be fully compatible with diethylene and triethylene glycol, but not to the ethylene one. Triple systems «Butyl benzyl phthalate - Diphenylcresylphosphate - Simple oligoesters» turned out to be homogeneous for several created compounds. To achieve this for a triple system, the minimal quantity threshold is either 20% of triethylene glycol or 30% of diethylene. As for the case of dioctyl phthalate for second plasticizer, the minimal threshold for blowing agents is 70%. We constructed a device that allows to detect phase equilibrium for liquid systems. We devised several compounds and a technological proccess for creating porous PVC-based membranes using thermal molding. We selected such molding due to several advantages when compared to other methods for producing porous membranes, such as: required density, elasticity, open pores, and narrow pore size distribution. We managed to create several samples based on emulsion type PVC, butyl benzyl phthalate, diphenylcresyl phosphate, diethylene and triethylene glycol. During the phase inversion thermal process temperature should be around 180 degrees of celsium. Porous materials have the following properties: open porosity 38-44%, breaking strength 1.0 – 1.2 MРa, relative extension 43-63%, maximal pore size (2.3 – 2.8)·10-6 m, average pore size (0.5 – 1.1)·10-6 m.
{"title":"RESEARCH FOR FORMING POROUS STRUCTURES BASED ON PVC","authors":"I. Khristoforova, A. Khristoforov","doi":"10.6060/ivkkt.20206305.6084","DOIUrl":"https://doi.org/10.6060/ivkkt.20206305.6084","url":null,"abstract":"In this work, we report on phase equilibrium in systems «plasticizer mix - blowing agent». Dioctiphthalate, butylbenzylphthalate and dicresyl phosphate were used as plasticizer, and simple oligoesters (ethylene glycol, diethylene glycol, triethylene glycol) served as a blowing agent. We conducted an experiment and built triple phase diagrams. Diphenylcresylphosphate proved to be fully compatible with diethylene and triethylene glycol, but not to the ethylene one. Triple systems «Butyl benzyl phthalate - Diphenylcresylphosphate - Simple oligoesters» turned out to be homogeneous for several created compounds. To achieve this for a triple system, the minimal quantity threshold is either 20% of triethylene glycol or 30% of diethylene. As for the case of dioctyl phthalate for second plasticizer, the minimal threshold for blowing agents is 70%. We constructed a device that allows to detect phase equilibrium for liquid systems. We devised several compounds and a technological proccess for creating porous PVC-based membranes using thermal molding. We selected such molding due to several advantages when compared to other methods for producing porous membranes, such as: required density, elasticity, open pores, and narrow pore size distribution. We managed to create several samples based on emulsion type PVC, butyl benzyl phthalate, diphenylcresyl phosphate, diethylene and triethylene glycol. During the phase inversion thermal process temperature should be around 180 degrees of celsium. Porous materials have the following properties: open porosity 38-44%, breaking strength 1.0 – 1.2 MРa, relative extension 43-63%, maximal pore size (2.3 – 2.8)·10-6 m, average pore size (0.5 – 1.1)·10-6 m.","PeriodicalId":14640,"journal":{"name":"IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79638517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-14DOI: 10.6060/ivkkt.20206305.5956
A. Kyarov, R. A. Mukozheva, M. Vindizheva, Idris Yu. Hochuev, R. S. Mirzoev
The solubility in the Cs2MoO4 – iso-C4H9OH – H2O system at 25 °C was studied for the first time. It is shown that in this system no formation of new compounds occurs. Isobutyl alcohol has limited solubility in water. This is confirmed by the fact that when cesium molybdate is added to the system, the mutual solubility of isobutyl alcohol and water decreases significantly. In the lower aqueous layer the solubility of C4H9OH in water is from 8.13 wt.%, in pure water to 0.04 wt.% of C4H9OH in a saturated 79.91% aqueous solution of Cs2MoO4; in the upper alcohol layer the solubility of water in isobutyl alcohol decreases from 16.90 to 0.51 wt.% of H2O in the presence of 0.0069 wt.% of Cs2MoO4. In the nonvariant state the saturated liquid phases (L1 and L2), which are in equilibrium with the solid phase of Cs2MoO4, have the composition (wt.%): L1 – 79.58 Cs2MoO4, 0.04 C4H9OH and 20.38 H2O; L2 – 0.069 Cs2MoO4, 99.48 C4H9OH and 0.51 H2O. Stratification is observed throughout the concentration range. In this system there is neither upper nor lower critical point of solubility and there is no binoidal solubility surface of the ternary system. Only two open sections of this surface appear which are displayed as two isolated curves on the projections of the spatial diagram. The density, refractive index, and dynamic viscosity of saturated solutions of the system were determined, and the isotherms of specific and molar volumes were calculated. The results of the study of physico-chemical properties of this system of saturated solutions show a regular change of all properties of conjugate liquid phases in accordance with the changes in their composition and character of interaction of components in the system.
{"title":"SOLUBILITY AND PHYSICOCHEMICAL PROPERTIES OF SATURATED SOLUTIONS IN CESIUM MOLYBDATE – ISOBUTYL ALCOHOL – WATER SYSTEM AT 25 °C","authors":"A. Kyarov, R. A. Mukozheva, M. Vindizheva, Idris Yu. Hochuev, R. S. Mirzoev","doi":"10.6060/ivkkt.20206305.5956","DOIUrl":"https://doi.org/10.6060/ivkkt.20206305.5956","url":null,"abstract":"The solubility in the Cs2MoO4 – iso-C4H9OH – H2O system at 25 °C was studied for the first time. It is shown that in this system no formation of new compounds occurs. Isobutyl alcohol has limited solubility in water. This is confirmed by the fact that when cesium molybdate is added to the system, the mutual solubility of isobutyl alcohol and water decreases significantly. In the lower aqueous layer the solubility of C4H9OH in water is from 8.13 wt.%, in pure water to 0.04 wt.% of C4H9OH in a saturated 79.91% aqueous solution of Cs2MoO4; in the upper alcohol layer the solubility of water in isobutyl alcohol decreases from 16.90 to 0.51 wt.% of H2O in the presence of 0.0069 wt.% of Cs2MoO4. In the nonvariant state the saturated liquid phases (L1 and L2), which are in equilibrium with the solid phase of Cs2MoO4, have the composition (wt.%): L1 – 79.58 Cs2MoO4, 0.04 C4H9OH and 20.38 H2O; L2 – 0.069 Cs2MoO4, 99.48 C4H9OH and 0.51 H2O. Stratification is observed throughout the concentration range. In this system there is neither upper nor lower critical point of solubility and there is no binoidal solubility surface of the ternary system. Only two open sections of this surface appear which are displayed as two isolated curves on the projections of the spatial diagram. The density, refractive index, and dynamic viscosity of saturated solutions of the system were determined, and the isotherms of specific and molar volumes were calculated. The results of the study of physico-chemical properties of this system of saturated solutions show a regular change of all properties of conjugate liquid phases in accordance with the changes in their composition and character of interaction of components in the system.","PeriodicalId":14640,"journal":{"name":"IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA","volume":"23 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141215168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-14DOI: 10.6060/ivkkt.20206305.6175
Andrey G. Starostin, N. B. Khodyashev
The work presents the results of a chemisorption analysis of a platinum-rhenium catalyst on an alumina support after regeneration and reduction with hydrogen. Adsorption-desorption diagrams were obtained by stepwise-pulsed chemisorption of carbon monoxide on reforming catalyst samples. With an increase in the number of carbon monoxide injections from 1 to 4, the catalyst sample is poisoned, and subsequent desorption peaks indicate the termination of the interaction. With an increase in the time of oxychlorination, the CO/Pt ratio in the carrier volume increases linearly. The effect of the oxychlorination process on the chemisorption of CO and the subsequent availability of platinum nanoparticles for catalysis has been shown. The absorption on freshly prepared platinum-rhenium catalyst samples reaches a CO/Pt molar ratio of about 0.4. The results show that the duration of oxychlorination for 16–20 h allows us to achieve the value of the ratio CO/Pt, which is in the range of 0.4-0.5. This indicates that the availability of platinum centers in its composition reaches the level of a fresh catalyst, and, on the other hand, taking into account a slight excess of this ratio, we can assume that some of the Re atoms participate in the absorption of CO molecules. The presence of finely dispersed platinum particles in the composition of the regenerated catalyst was confirmed by IR spectroscopy. The analysis of catalyst samples on an IR spectrometer in the frequency range of 1900-2200 cm-1 revealed a rather wide absorption band with a pronounced extremum at 2060 cm-1. In this frequency range, there is another, slightly pronounced extremum at 2149 cm-1. However, for samples with a short duration of oxychlorination, it did not appear. An absorption band with an extremum of 2060 cm-1 can be attributed to linear vibrations of adsorbed CO molecules on the surface of particles of metallic platinum.
{"title":"EFFECT OF DURATION OF OXYCHLORINATION ON DEGREE OF ACCESSIBILITY FOR CATALYSIS OF PLATINUM CENTERS OF PLATINUM-RHENIUM REFORMING CATALYST","authors":"Andrey G. Starostin, N. B. Khodyashev","doi":"10.6060/ivkkt.20206305.6175","DOIUrl":"https://doi.org/10.6060/ivkkt.20206305.6175","url":null,"abstract":"The work presents the results of a chemisorption analysis of a platinum-rhenium catalyst on an alumina support after regeneration and reduction with hydrogen. Adsorption-desorption diagrams were obtained by stepwise-pulsed chemisorption of carbon monoxide on reforming catalyst samples. With an increase in the number of carbon monoxide injections from 1 to 4, the catalyst sample is poisoned, and subsequent desorption peaks indicate the termination of the interaction. With an increase in the time of oxychlorination, the CO/Pt ratio in the carrier volume increases linearly. The effect of the oxychlorination process on the chemisorption of CO and the subsequent availability of platinum nanoparticles for catalysis has been shown. The absorption on freshly prepared platinum-rhenium catalyst samples reaches a CO/Pt molar ratio of about 0.4. The results show that the duration of oxychlorination for 16–20 h allows us to achieve the value of the ratio CO/Pt, which is in the range of 0.4-0.5. This indicates that the availability of platinum centers in its composition reaches the level of a fresh catalyst, and, on the other hand, taking into account a slight excess of this ratio, we can assume that some of the Re atoms participate in the absorption of CO molecules. The presence of finely dispersed platinum particles in the composition of the regenerated catalyst was confirmed by IR spectroscopy. The analysis of catalyst samples on an IR spectrometer in the frequency range of 1900-2200 cm-1 revealed a rather wide absorption band with a pronounced extremum at 2060 cm-1. In this frequency range, there is another, slightly pronounced extremum at 2149 cm-1. However, for samples with a short duration of oxychlorination, it did not appear. An absorption band with an extremum of 2060 cm-1 can be attributed to linear vibrations of adsorbed CO molecules on the surface of particles of metallic platinum.","PeriodicalId":14640,"journal":{"name":"IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA","volume":"213 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76667568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-08DOI: 10.6060/ivkkt.20206303.6091
Inna Slepchuk, O. Semeshko, T. Asaulyuk, Yuliya G. Saribyekova
The results of the study of the physicochemical properties of styrene-acrylic and urethane polymer films, as well as polymer compositions based on the studied polymers with the addition of crosslinking agents are presented. Aqueous dispersions of styrene-acrylic polymers Lacritex 309, Lacritex 430, Lacritex 640 and polyurethane polymer Aquapol 14 were used for the formation of films. Triglycidyl esthers of polyoxypropylene triol and trimethylolpropane — Laproxid 703 and Laproxid TMP — were used as crosslinking agents. The stability of polymer films to hydrolytic destruction was evaluated after treatment at 20, 40 and 100 °C, and to the soap-soda treatment — at 40 °C. It was found that the most resistant to hydrolysis and soap-soda treatment are films from styrene-acrylic polymer Lacritex 309 and compositions Lacritex 640 / Laproxid 703, Aquapol 14 / Laproxid TMP, Aquapol 14 / Laproxid 703. The tensile load, elongation at break, stiffness and surface tackiness were also determined for the studied polymer films. It was found that polymer films based on Lacritex 309 and compositions Lacritex 640 / Laproxid 703, Aquapol 14 / Laproxid 703 are characterized by the greatest strength and elongation, non-rigid and non-tacky surface. Adding Laproxid TMP to polyurethane Aquapol 14 provides creation of a solid and inelastic film. To assess the effect of polymer coatings on the textile material rigidity, a cotton fabric with twill weave was used, which is used for special work clothes. Polymers and their compositions were applied to the fabric from a solution with a concentration of 150 g/l, followed by drying and heat setting. For dressed cotton fabric, rigidity and breaking load were determined. The rigidity of the treated cotton fabric was determined by the method of console. It has been established that the use of polyurethane Aquapol 14 and compositions based on it, as well as styrene-acrylic dispersions Lacritex 309 and Lacritex 430 will result in hard handle of textile materials. The composition based on Lacritex 640 with the addition of Laproxid 703 as a crosslinker provides an elastic and strong textile material.
{"title":"INVESTIGATION OF PHYSICOCHEMICAL PROPERTIES OF STYRENE-ACRYLIC AND URETHANE POLYMERS USED IN FINISHING OF TEXTILE MATERIALS","authors":"Inna Slepchuk, O. Semeshko, T. Asaulyuk, Yuliya G. Saribyekova","doi":"10.6060/ivkkt.20206303.6091","DOIUrl":"https://doi.org/10.6060/ivkkt.20206303.6091","url":null,"abstract":"The results of the study of the physicochemical properties of styrene-acrylic and urethane polymer films, as well as polymer compositions based on the studied polymers with the addition of crosslinking agents are presented. Aqueous dispersions of styrene-acrylic polymers Lacritex 309, Lacritex 430, Lacritex 640 and polyurethane polymer Aquapol 14 were used for the formation of films. Triglycidyl esthers of polyoxypropylene triol and trimethylolpropane — Laproxid 703 and Laproxid TMP — were used as crosslinking agents. The stability of polymer films to hydrolytic destruction was evaluated after treatment at 20, 40 and 100 °C, and to the soap-soda treatment — at 40 °C. It was found that the most resistant to hydrolysis and soap-soda treatment are films from styrene-acrylic polymer Lacritex 309 and compositions Lacritex 640 / Laproxid 703, Aquapol 14 / Laproxid TMP, Aquapol 14 / Laproxid 703. The tensile load, elongation at break, stiffness and surface tackiness were also determined for the studied polymer films. It was found that polymer films based on Lacritex 309 and compositions Lacritex 640 / Laproxid 703, Aquapol 14 / Laproxid 703 are characterized by the greatest strength and elongation, non-rigid and non-tacky surface. Adding Laproxid TMP to polyurethane Aquapol 14 provides creation of a solid and inelastic film. To assess the effect of polymer coatings on the textile material rigidity, a cotton fabric with twill weave was used, which is used for special work clothes. Polymers and their compositions were applied to the fabric from a solution with a concentration of 150 g/l, followed by drying and heat setting. For dressed cotton fabric, rigidity and breaking load were determined. The rigidity of the treated cotton fabric was determined by the method of console. It has been established that the use of polyurethane Aquapol 14 and compositions based on it, as well as styrene-acrylic dispersions Lacritex 309 and Lacritex 430 will result in hard handle of textile materials. The composition based on Lacritex 640 with the addition of Laproxid 703 as a crosslinker provides an elastic and strong textile material.","PeriodicalId":14640,"journal":{"name":"IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA","volume":"158 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74378457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-08DOI: 10.6060/ivkkt.20206303.6126
N. G. Vilkova, S. Mishina, E. D. Deputatov
The properties of foams stabilized by hydrophobized titanium oxide and silica are studied. It was shown that when hexylamine was added to silica suspensions (in an amount of ≥ 10 mmol/l), the values of the hydrogen index corresponded to the alkaline region. Moreover, the stability of such foams increases with the increasing concentration of hexylamine and an increase in the relative degree of hydrophobization to ng = 2.75 mmol/g. However, rapid destruction of disperse systems is possible when a certain degree of hydrophobization is achieved (for example, ng≥3 in aerosil suspensions), which is due to aggregation of particles in the initial suspension. The dependence of the lifetime of these dispersed systems on the hydrogen index (pH) is shown. The most stable disperse systems were formed at the pH value of 5, which is close to the isoelectric point of the oxide. Foams obtained from the suspension of the composition: 20% titanium oxide + 76.6 mmol/l hexylamine remained stable for four days or more at pH = 5 and a change in the relative hydrophobicity of the surface (ng) from 0.383 to 1.27 mmol/g. With a significant increase in the degree of hydrophobization of the surface to 4.6 mmol/g and the same pH value, foaming was insignificant (the layer height (h) was 0.2 cm) and life time t≈10 sec. Probably fixing the particles at the liquid-gas interface is an irreversible process only when a certain degree of hydrophobicity is achieved. To explain the possible causes of change stability of the foam containing the titanium dioxide from the pH we have investigated the distribution of particles according to their sizes by the method of sedimentation analysis. It was found that at pH=10 the fractional composition of the suspension with an average radius of 3 µm was equal to 50%, at the same time the maximum radius was 21 µm; the value of the wetting angle of the particles was equal to 40.8º. In an acidic medium (pH=2-3) and at pH=5, the fraction content with an average particle radius of 5 µm was 29% and 30%, respectively. However, low (14.7º) values of the wetting angle at pH=2 can cause low stability of foams in an acidic environment. Highly stable foams were obtained by changing the viscosity of the dispersion medium in suspensions of hydrophobized titanium oxide. When adding glycerol to the suspension composition: 9.0% titanium dioxide + 0.7% hexylamine, pH=9, gel foam was obtained, which was not destroyed within 10 days. However, in an acidic medium with the addition of the same amount of glycerol, the formation of a stable dispersed system was not observed.
{"title":"FOAMS STABILIZATION BY HYDROPHOBIZED OXIDES OF VARIOUS CHEMICAL NATURE","authors":"N. G. Vilkova, S. Mishina, E. D. Deputatov","doi":"10.6060/ivkkt.20206303.6126","DOIUrl":"https://doi.org/10.6060/ivkkt.20206303.6126","url":null,"abstract":"The properties of foams stabilized by hydrophobized titanium oxide and silica are studied. It was shown that when hexylamine was added to silica suspensions (in an amount of ≥ 10 mmol/l), the values of the hydrogen index corresponded to the alkaline region. Moreover, the stability of such foams increases with the increasing concentration of hexylamine and an increase in the relative degree of hydrophobization to ng = 2.75 mmol/g. However, rapid destruction of disperse systems is possible when a certain degree of hydrophobization is achieved (for example, ng≥3 in aerosil suspensions), which is due to aggregation of particles in the initial suspension. The dependence of the lifetime of these dispersed systems on the hydrogen index (pH) is shown. The most stable disperse systems were formed at the pH value of 5, which is close to the isoelectric point of the oxide. Foams obtained from the suspension of the composition: 20% titanium oxide + 76.6 mmol/l hexylamine remained stable for four days or more at pH = 5 and a change in the relative hydrophobicity of the surface (ng) from 0.383 to 1.27 mmol/g. With a significant increase in the degree of hydrophobization of the surface to 4.6 mmol/g and the same pH value, foaming was insignificant (the layer height (h) was 0.2 cm) and life time t≈10 sec. Probably fixing the particles at the liquid-gas interface is an irreversible process only when a certain degree of hydrophobicity is achieved. To explain the possible causes of change stability of the foam containing the titanium dioxide from the pH we have investigated the distribution of particles according to their sizes by the method of sedimentation analysis. It was found that at pH=10 the fractional composition of the suspension with an average radius of 3 µm was equal to 50%, at the same time the maximum radius was 21 µm; the value of the wetting angle of the particles was equal to 40.8º. In an acidic medium (pH=2-3) and at pH=5, the fraction content with an average particle radius of 5 µm was 29% and 30%, respectively. However, low (14.7º) values of the wetting angle at pH=2 can cause low stability of foams in an acidic environment. Highly stable foams were obtained by changing the viscosity of the dispersion medium in suspensions of hydrophobized titanium oxide. When adding glycerol to the suspension composition: 9.0% titanium dioxide + 0.7% hexylamine, pH=9, gel foam was obtained, which was not destroyed within 10 days. However, in an acidic medium with the addition of the same amount of glycerol, the formation of a stable dispersed system was not observed.","PeriodicalId":14640,"journal":{"name":"IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87971489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-08DOI: 10.6060/ivkkt.20206302.6073
Anastasiya N. Zhanakhova, B. Dyskina, N. V. Negutorov, N. V. Pykhova
Thermally expanded graphite is obtained from crucible graphite by treatment with oleum in the presence of an oxidizing agent. The obtained samples of thermally expanded graphite were subjected to ultrasonic dispersion (splitting up) in four liquid media (water, toluene, benzene, acetone). It was shown that in the process of ultrasonic dispersion (splitting), the initial thermally expanded graphite is split into plates with a thickness of several tens to hundreds of nanometers. However, the plates are not single, but are in chaotic clusters with each other. The free bonds of carbon atoms, which are located at the edges of the plates, can play an important role in chemical processes and in the adsorption of substances on the surface of particles of split graphite. It was found that a high degree of perfection of the crystal structure, which is typical of the original graphite, is retained during ultrasonic treatment as compared with mechanical splitting. The change in the specific surface of graphite samples is presented. The main increase in the specific surface of the particles during ultrasonic splitting is created by increasing the area of the surfaces formed during interplanar splitting of graphite plates. Based on the comparison of this parameter, the effect of the used liquids on the splitting process is considered. The high values of the specific surface of the samples split in benzene and toluene are explained by the low values of the surface tension. The good wettability of the graphite surface with benzene, toluene and acetone compared with water allows these liquids to penetrate deep into the pores of graphite. Due to this, maximum splitting is achieved with ultrasonic processing of the mixture. Conclusions on the choice of the optimal liquid medium for dispersing graphite are made.
{"title":"FEATURES OF ULTRASONIC SPLITTING OF THERMALLY EXPANDED GRAPHITE","authors":"Anastasiya N. Zhanakhova, B. Dyskina, N. V. Negutorov, N. V. Pykhova","doi":"10.6060/ivkkt.20206302.6073","DOIUrl":"https://doi.org/10.6060/ivkkt.20206302.6073","url":null,"abstract":"Thermally expanded graphite is obtained from crucible graphite by treatment with oleum in the presence of an oxidizing agent. The obtained samples of thermally expanded graphite were subjected to ultrasonic dispersion (splitting up) in four liquid media (water, toluene, benzene, acetone). It was shown that in the process of ultrasonic dispersion (splitting), the initial thermally expanded graphite is split into plates with a thickness of several tens to hundreds of nanometers. However, the plates are not single, but are in chaotic clusters with each other. The free bonds of carbon atoms, which are located at the edges of the plates, can play an important role in chemical processes and in the adsorption of substances on the surface of particles of split graphite. It was found that a high degree of perfection of the crystal structure, which is typical of the original graphite, is retained during ultrasonic treatment as compared with mechanical splitting. The change in the specific surface of graphite samples is presented. The main increase in the specific surface of the particles during ultrasonic splitting is created by increasing the area of the surfaces formed during interplanar splitting of graphite plates. Based on the comparison of this parameter, the effect of the used liquids on the splitting process is considered. The high values of the specific surface of the samples split in benzene and toluene are explained by the low values of the surface tension. The good wettability of the graphite surface with benzene, toluene and acetone compared with water allows these liquids to penetrate deep into the pores of graphite. Due to this, maximum splitting is achieved with ultrasonic processing of the mixture. Conclusions on the choice of the optimal liquid medium for dispersing graphite are made.","PeriodicalId":14640,"journal":{"name":"IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84498602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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