Pub Date : 2023-08-02DOI: 10.32362/2410-6593-2023-18-3-243-253
E. A. Trofimenko, T. V. Bukharkina, S. V. Verzhichinskaya
Objectives. The work set out to modify the technology of accelerated thermal stabilization of polyacrylonitrile (PAN) fibers used in the production of high-strength carbon fibers by reducing the formation of a heterophase core–shell structure to create an oxygen concentration gradient in heat treatment furnaces while maintaining a total thermal stabilization time of 30 min. The optimized process conditions led to milder thermal stabilization conditions, reducing both the final heat treatment temperature and the temperature difference between the thermal stabilization zones while simultaneously maintaining the target volume density parameter with respect to the previously developed accelerated thermal stabilization technology.Methods. The thermal stabilization study of an industrially produced 12S precursor under different conditions on an experimental carbon fiber production line included measurement of bulk density, analysis of the thermal effects of the oxidation reaction by differential scanning calorimetry (DSC), and a study of micrographs of the resulting samples.Results. The optimum process of thermal stabilization of PAN fiber was determined in four stabilization zones using selected compositions. The formation of the core–shell structure is significantly reduced when the target volume density and DSC thermal oxidation reaction effect of the stabilized polymer fiber are achieved in a given time (30 min).Conclusions. The resulting technology regime is promising for the production of high strength (4.5 GPa, 4.9 GPa) PAN fibers at a reduced cost. While maintaining the total thermal stabilization time of PAN at the level of 30 min, which is three times less than the industrial processes used, it was possible to reduce the formation of a heterophase structure, as well as lowering the final processing temperature and reducing the temperature difference between the stabilization zones. This is promising in terms of a positive effect on the stability and safety of the industrial process, as well as ensuring the quality of the obtained products.
{"title":"Modification of accelerated thermal stabilization of polyacrylonitrile fibers by creating an oxygen concentration gradient in the production of carbon fiber","authors":"E. A. Trofimenko, T. V. Bukharkina, S. V. Verzhichinskaya","doi":"10.32362/2410-6593-2023-18-3-243-253","DOIUrl":"https://doi.org/10.32362/2410-6593-2023-18-3-243-253","url":null,"abstract":"Objectives. The work set out to modify the technology of accelerated thermal stabilization of polyacrylonitrile (PAN) fibers used in the production of high-strength carbon fibers by reducing the formation of a heterophase core–shell structure to create an oxygen concentration gradient in heat treatment furnaces while maintaining a total thermal stabilization time of 30 min. The optimized process conditions led to milder thermal stabilization conditions, reducing both the final heat treatment temperature and the temperature difference between the thermal stabilization zones while simultaneously maintaining the target volume density parameter with respect to the previously developed accelerated thermal stabilization technology.Methods. The thermal stabilization study of an industrially produced 12S precursor under different conditions on an experimental carbon fiber production line included measurement of bulk density, analysis of the thermal effects of the oxidation reaction by differential scanning calorimetry (DSC), and a study of micrographs of the resulting samples.Results. The optimum process of thermal stabilization of PAN fiber was determined in four stabilization zones using selected compositions. The formation of the core–shell structure is significantly reduced when the target volume density and DSC thermal oxidation reaction effect of the stabilized polymer fiber are achieved in a given time (30 min).Conclusions. The resulting technology regime is promising for the production of high strength (4.5 GPa, 4.9 GPa) PAN fibers at a reduced cost. While maintaining the total thermal stabilization time of PAN at the level of 30 min, which is three times less than the industrial processes used, it was possible to reduce the formation of a heterophase structure, as well as lowering the final processing temperature and reducing the temperature difference between the stabilization zones. This is promising in terms of a positive effect on the stability and safety of the industrial process, as well as ensuring the quality of the obtained products.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88372177","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 : 2023-08-02DOI: 10.32362/2410-6593-2023-18-3-175-186
Yuriy L. Zotov, D. M. Zapravdina, E. Shishkin, Y. Popov
Objectives. To investigate the catalytic activity of calcium-containing basic catalysts for the esterification of glycerol with higher carboxylic acids in order to develop a low-waste technology for the production of multifunctional additives, as well as to assess the possibility of using the reaction products for the processing of polyvinyl chloride.Methods. The consumption of oleic acid during synthesis was monitored using a titrimetric method of analysis with visual indication. The structure of the synthesized calcium-containing catalysts was confirmed by infrared spectroscopy; elemental analysis was additionally performed for calcium glyceroxide. Quantitative and qualitative analyses of the resulting mixtures of oleic acid glycerides were carried out using chromato-mass spectrometry. A sample of a multifunctional additive was tested in a model formulation of a medical plastic compound based on polyvinyl chloride.Results. It is shown that the catalytic activity of calcium derivatives in the reaction of esterification of glycerol with higher carboxylic acids increases in the series СаО < Са(ОН)2 < Ca(C17H33COO)2 < Ca(C2H5O)2 < Ca(C4H9O)2 < Ca(C3H7O3)2, while the use of calcium glyceroxide as a catalyst in an amount from 1 to 6 mol % increases the conversion of carboxylic acid from 58 to 86% in 10 h of synthesis. However, varying the amount of calcium glyceroxide from 1.5 to 6 mol % results in no observed changes in the conversion of carboxylic acid. The multifunctional additive obtained by selecting calcium glyceroxide as a catalyst has a thermally stabilizing and plasticizing effect on the polymer composition. The introduction of the developed additive into the formulation of a polyvinyl chloride composition for medical purposes reduces the processing torque and time to reach the dry point. By combining these factors, energy costs during production were reduced by more than 11% compared to the control composition.Conclusions. It is established that calcium alcoholates catalyze the reaction of esterification of glycerol with oleic (or higher) acid to increase the conversion of the initial substances and selectivity for the formation of monoglycerides as compared with calcium oxide, hydroxide, and oleate. By optimizing the ratio of glycerol : oleic acid : calcium glyceroxide at 1 : 1 : 0.015, the maximum conversion of oleic acid of up to 86% in 10 h was obtained via synthesis. The proposed method for esterification of glycerol with higher carboxylic acids in the presence of a calcium-containing catalyst avoids the stage of purification from the catalyst to obtain a composition with multifunctional additive properties for the processing of polyvinyl chloride.
{"title":"Study of calcium-containing compounds as catalysts for the esterification of glycerol with higher carboxylic acids","authors":"Yuriy L. Zotov, D. M. Zapravdina, E. Shishkin, Y. Popov","doi":"10.32362/2410-6593-2023-18-3-175-186","DOIUrl":"https://doi.org/10.32362/2410-6593-2023-18-3-175-186","url":null,"abstract":"Objectives. To investigate the catalytic activity of calcium-containing basic catalysts for the esterification of glycerol with higher carboxylic acids in order to develop a low-waste technology for the production of multifunctional additives, as well as to assess the possibility of using the reaction products for the processing of polyvinyl chloride.Methods. The consumption of oleic acid during synthesis was monitored using a titrimetric method of analysis with visual indication. The structure of the synthesized calcium-containing catalysts was confirmed by infrared spectroscopy; elemental analysis was additionally performed for calcium glyceroxide. Quantitative and qualitative analyses of the resulting mixtures of oleic acid glycerides were carried out using chromato-mass spectrometry. A sample of a multifunctional additive was tested in a model formulation of a medical plastic compound based on polyvinyl chloride.Results. It is shown that the catalytic activity of calcium derivatives in the reaction of esterification of glycerol with higher carboxylic acids increases in the series СаО < Са(ОН)2 < Ca(C17H33COO)2 < Ca(C2H5O)2 < Ca(C4H9O)2 < Ca(C3H7O3)2, while the use of calcium glyceroxide as a catalyst in an amount from 1 to 6 mol % increases the conversion of carboxylic acid from 58 to 86% in 10 h of synthesis. However, varying the amount of calcium glyceroxide from 1.5 to 6 mol % results in no observed changes in the conversion of carboxylic acid. The multifunctional additive obtained by selecting calcium glyceroxide as a catalyst has a thermally stabilizing and plasticizing effect on the polymer composition. The introduction of the developed additive into the formulation of a polyvinyl chloride composition for medical purposes reduces the processing torque and time to reach the dry point. By combining these factors, energy costs during production were reduced by more than 11% compared to the control composition.Conclusions. It is established that calcium alcoholates catalyze the reaction of esterification of glycerol with oleic (or higher) acid to increase the conversion of the initial substances and selectivity for the formation of monoglycerides as compared with calcium oxide, hydroxide, and oleate. By optimizing the ratio of glycerol : oleic acid : calcium glyceroxide at 1 : 1 : 0.015, the maximum conversion of oleic acid of up to 86% in 10 h was obtained via synthesis. The proposed method for esterification of glycerol with higher carboxylic acids in the presence of a calcium-containing catalyst avoids the stage of purification from the catalyst to obtain a composition with multifunctional additive properties for the processing of polyvinyl chloride.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79397807","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 : 2023-05-27DOI: 10.32362/2410-6593-2023-18-2-123-134
I. Vasilyev
Objectives. To obtain and study the properties including degradability of polymer composite materials (PCM) based on low-density polyethylene (LDPE) obtained by introducing an environmentally friendly additive comprising an oxo-decomposing additive (ODA) based on an amphiphilic polymer-iron metal complex, which accelerates the process of polymer degradation.Methods. PCMs based on LDPE and ODA were produced by processing in laboratory extruders in the form of strands, granules, and films. Thermodynamic properties were determined by differential scanning calorimetry in the temperature range 20-130 °C. In order to assess the performance characteristics (physical and mechanical properties) of the PCM, tensile strength and elongation at break were determined. The biodegradability of PCM was evaluated by Sturm's method, with the biodegradation index being determined by the amount of CO2 gas released as a result of microorganism activity, as well as composting by placing the PCMs for six months in biohumus. Changes in physical and mechanical properties and water absorption of the films during storage were evaluated. The photochemical degradability of the PCM was determined by exposing it to ultraviolet radiation for 100 h (equivalent to approximately one year of exposure of the films under natural conditions). The appearance of the composite samples following removal from the biohumus was determined using an optical microscope with ×50 magnification in transmitted and reflected light.Results. Following biodegradation by composting, the physical and mechanical properties of PCMs decrease by an average of 40.6%. This is related to the structural changes that occur in composites during storage in biohumus, i.e., the formation of a looser structure due to the development of large clusters of microorganisms that affect the formation of microcracks. It leads to the stage of fragmentation of the polyethylene matrix and indicates the progress of biological degradation of composites. In this case, the water absorption of the composite samples was 63% after 96 h of exposure. The biodegradability index determined by the Sturm method after 28 days of bubbling had changed by 82%, indicating an intensive biodegradation process. Exposure to ultraviolet radiation for 96 h resulted in the complete destruction of the PCMs, which turned into small “flakes.” This method is the most effective for the degradation of LDPE- and ODA-based PCMs.Conclusions. According to the results of the study of ODA-containing PCMs based on an amphiphilic polymer-iron metal complex, the tested filler-modifier can be recommended for the production of PCMs offering an accelerated degradation period.
{"title":"Biocomposite materials based on polyethylene and amphiphilic polymer-iron metal complex","authors":"I. Vasilyev","doi":"10.32362/2410-6593-2023-18-2-123-134","DOIUrl":"https://doi.org/10.32362/2410-6593-2023-18-2-123-134","url":null,"abstract":"Objectives. To obtain and study the properties including degradability of polymer composite materials (PCM) based on low-density polyethylene (LDPE) obtained by introducing an environmentally friendly additive comprising an oxo-decomposing additive (ODA) based on an amphiphilic polymer-iron metal complex, which accelerates the process of polymer degradation.Methods. PCMs based on LDPE and ODA were produced by processing in laboratory extruders in the form of strands, granules, and films. Thermodynamic properties were determined by differential scanning calorimetry in the temperature range 20-130 °C. In order to assess the performance characteristics (physical and mechanical properties) of the PCM, tensile strength and elongation at break were determined. The biodegradability of PCM was evaluated by Sturm's method, with the biodegradation index being determined by the amount of CO2 gas released as a result of microorganism activity, as well as composting by placing the PCMs for six months in biohumus. Changes in physical and mechanical properties and water absorption of the films during storage were evaluated. The photochemical degradability of the PCM was determined by exposing it to ultraviolet radiation for 100 h (equivalent to approximately one year of exposure of the films under natural conditions). The appearance of the composite samples following removal from the biohumus was determined using an optical microscope with ×50 magnification in transmitted and reflected light.Results. Following biodegradation by composting, the physical and mechanical properties of PCMs decrease by an average of 40.6%. This is related to the structural changes that occur in composites during storage in biohumus, i.e., the formation of a looser structure due to the development of large clusters of microorganisms that affect the formation of microcracks. It leads to the stage of fragmentation of the polyethylene matrix and indicates the progress of biological degradation of composites. In this case, the water absorption of the composite samples was 63% after 96 h of exposure. The biodegradability index determined by the Sturm method after 28 days of bubbling had changed by 82%, indicating an intensive biodegradation process. Exposure to ultraviolet radiation for 96 h resulted in the complete destruction of the PCMs, which turned into small “flakes.” This method is the most effective for the degradation of LDPE- and ODA-based PCMs.Conclusions. According to the results of the study of ODA-containing PCMs based on an amphiphilic polymer-iron metal complex, the tested filler-modifier can be recommended for the production of PCMs offering an accelerated degradation period.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78457499","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 : 2023-05-27DOI: 10.32362/2410-6593-2023-18-2-135-167
A. Ischenko, M. Lazov, E. Mironova, A. Y. Putin, A. Ionov, P. Storozhenko
Objectives. The main aim of this review is to summarize the existing knowledge on the use of X-ray photoelectron spectroscopy (XPS) for the characterization of nanoparticles and nanomaterials.Results. XPS or electron spectroscopy for chemical analysis can provide information on the qualitative and quantitative composition, valence states of the elements of the samples under study, the chemical composition of the surface and interfaces that determine the properties of nanoparticles and nanostructured materials. The review describes the role of several different methods for the characterization of nanomaterials, highlights their advantages and limitations, and the possibilities of an effective combination. The main characteristics of XPS are described. Various examples of its use for the analysis of nanoparticles and nanomaterials are given in conjunction with additional methods to obtain complementary information about the object under study.Conclusions. XPS provides depth information comparable to the size of nanoparticles (up to 10 nm depth from the surface) and does not cause significant damage to the samples. Two disadvantages of XPS analysis are sample preparation requiring a dry solid form without contaminations and data interpretation. XPS provides information not only on the chemical identity, but also on the dielectric properties of nanomaterials, recording their charging/discharging behavior. Chemical information from the surface of nanoparticles analyzed by XPS can be used to estimate the thickness of nanoparticle coatings. XPS has a high selectivity, since the resolution of the method makes it possible to distinguish a characteristic set of lines in the photoelectron spectrum at kinetic energies determined by the photon energy and the corresponding binding energies in elements. The intensity of the lines depends on the concentration of the respective element. Obtaining a sufficiently complete picture of the properties of nanomaterials requires the use of a group of complementary instrumental methods of analysis.
{"title":"Analysis of nanoparticles and nanomaterials using X-ray photoelectron spectroscopy","authors":"A. Ischenko, M. Lazov, E. Mironova, A. Y. Putin, A. Ionov, P. Storozhenko","doi":"10.32362/2410-6593-2023-18-2-135-167","DOIUrl":"https://doi.org/10.32362/2410-6593-2023-18-2-135-167","url":null,"abstract":"Objectives. The main aim of this review is to summarize the existing knowledge on the use of X-ray photoelectron spectroscopy (XPS) for the characterization of nanoparticles and nanomaterials.Results. XPS or electron spectroscopy for chemical analysis can provide information on the qualitative and quantitative composition, valence states of the elements of the samples under study, the chemical composition of the surface and interfaces that determine the properties of nanoparticles and nanostructured materials. The review describes the role of several different methods for the characterization of nanomaterials, highlights their advantages and limitations, and the possibilities of an effective combination. The main characteristics of XPS are described. Various examples of its use for the analysis of nanoparticles and nanomaterials are given in conjunction with additional methods to obtain complementary information about the object under study.Conclusions. XPS provides depth information comparable to the size of nanoparticles (up to 10 nm depth from the surface) and does not cause significant damage to the samples. Two disadvantages of XPS analysis are sample preparation requiring a dry solid form without contaminations and data interpretation. XPS provides information not only on the chemical identity, but also on the dielectric properties of nanomaterials, recording their charging/discharging behavior. Chemical information from the surface of nanoparticles analyzed by XPS can be used to estimate the thickness of nanoparticle coatings. XPS has a high selectivity, since the resolution of the method makes it possible to distinguish a characteristic set of lines in the photoelectron spectrum at kinetic energies determined by the photon energy and the corresponding binding energies in elements. The intensity of the lines depends on the concentration of the respective element. Obtaining a sufficiently complete picture of the properties of nanomaterials requires the use of a group of complementary instrumental methods of analysis.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84936397","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 : 2023-05-27DOI: 10.32362/2410-6593-2023-18-2-98-108
I. N. Kolesnikova, N. V. Lobanov, V. N. Lobanov, I. F. Shishkov
Objectives. The study set out to determine the equilibrium parameters of the 3,4-dicyanofuroxan molecule by means of molecule geometry optimization by quantum chemistry methods, verify the adequacy of the methods used, and compare the obtained results with X-ray diffraction analysis (XRD) and gas electron diffraction (GED) data.Methods. Quantum chemical calculations were carried out using B3LYP, MP2, and CCSD(T) methods with 6-31G(d,p), cc-pVTZ, and aug-cc-pVTZ basis sets.Results. The equilibrium molecular structure of 3,4-dicyanofuroxan was refined by means of quantum chemical calculations using the Gaussian09 program. The geometrical parameters were compared with the structure of this compound in the solid phase and a number of related compounds in gas and solid phases. It was theoretically established that the planar equilibrium structure of the dicyanofuroxan molecule has CS symmetry. The structure of the free dicyanofuroxan molecule was found to differ depending on the phase. The B3LYP and CCSD(T) methods describe the molecular structure of dicyanofuroxan more accurately than the MP2 method. A regularity was revealed, according to which an increase in the basis, as a rule, leads to a better agreement of the geometry, regardless of the functional.Conclusions. The calculations performed are in good agreement with the literature data and results of joint analysis by GED and XRD. The effect of cyano substituents on the ring geometry is observed in comparison with the literature data for the dicyanofuroxan molecule. For the molecule in question, it is better to use the B3LYP/aug-cc-pVTZ method. The values of geometric parameters obtained by this method are in better agreement with the structure in the gas phase. The discrepancies with the experimental XRD results may be due to interactions in the crystal structure. Differences in the geometric parameters obtained on the basis of different functionals and bases make this molecule interesting for experimental structural studies using GED or microwave spectroscopy, which will permit the identification of optimal methods and bases for obtaining the geometric parameters of furoxan class molecules.
{"title":"Quantum chemical research of the molecular structure of 3,4-dicyanofuroxan","authors":"I. N. Kolesnikova, N. V. Lobanov, V. N. Lobanov, I. F. Shishkov","doi":"10.32362/2410-6593-2023-18-2-98-108","DOIUrl":"https://doi.org/10.32362/2410-6593-2023-18-2-98-108","url":null,"abstract":"Objectives. The study set out to determine the equilibrium parameters of the 3,4-dicyanofuroxan molecule by means of molecule geometry optimization by quantum chemistry methods, verify the adequacy of the methods used, and compare the obtained results with X-ray diffraction analysis (XRD) and gas electron diffraction (GED) data.Methods. Quantum chemical calculations were carried out using B3LYP, MP2, and CCSD(T) methods with 6-31G(d,p), cc-pVTZ, and aug-cc-pVTZ basis sets.Results. The equilibrium molecular structure of 3,4-dicyanofuroxan was refined by means of quantum chemical calculations using the Gaussian09 program. The geometrical parameters were compared with the structure of this compound in the solid phase and a number of related compounds in gas and solid phases. It was theoretically established that the planar equilibrium structure of the dicyanofuroxan molecule has CS symmetry. The structure of the free dicyanofuroxan molecule was found to differ depending on the phase. The B3LYP and CCSD(T) methods describe the molecular structure of dicyanofuroxan more accurately than the MP2 method. A regularity was revealed, according to which an increase in the basis, as a rule, leads to a better agreement of the geometry, regardless of the functional.Conclusions. The calculations performed are in good agreement with the literature data and results of joint analysis by GED and XRD. The effect of cyano substituents on the ring geometry is observed in comparison with the literature data for the dicyanofuroxan molecule. For the molecule in question, it is better to use the B3LYP/aug-cc-pVTZ method. The values of geometric parameters obtained by this method are in better agreement with the structure in the gas phase. The discrepancies with the experimental XRD results may be due to interactions in the crystal structure. Differences in the geometric parameters obtained on the basis of different functionals and bases make this molecule interesting for experimental structural studies using GED or microwave spectroscopy, which will permit the identification of optimal methods and bases for obtaining the geometric parameters of furoxan class molecules.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88838659","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 : 2023-05-27DOI: 10.32362/2410-6593-2023-18-2-109-122
K. A. Brekhova, I. D. Simonov-Emel'yanov, A. Pykhtin
Objectives. To identify general principles for the design of dispersed-filled polymer composite materials (DFPCMs) with different generalized and reduced parameters, as well as types of disperse structure with high fire resistance; to develop an algorithm for the creation of non-combustible polymer composites with flame-retardant fillers.Methods. Scanning electron microscopy and laser diffraction were used to assess the shape, size, and particle size distribution of flame retardants. According to the presented classification of DFPCMs by structural principle, standard bar samples were obtained to determine the oxygen index (OI) and the fire resistance category.Results. For the MFS-2 (medium filled system) and HFS (high filled system) structure types, the maximum resistance to burning (category V-0) is achieved with a generalized parameter of ® ≤ 0.40 volume fractions; the OI value increases in 2 times (up to ~40%) in relation to the polymer matrix.Conclusions. In order to obtain a flame retardant DFPCMs (OI = 40%, category V-0) based on ethylene vinyl acetate with OI = 20% and magnesium hydroxide (brucite), the amount of water vapor released during the decomposition of the flame-retardant filler should be at least ~250 mL/g with a coke residue ~32%. A developed algorithm for calculating compositions and generalized parameters for the creation of DFPCMs having a predetermined type of disperse structure and high resistance to burning is presented.
{"title":"Projection of structure and compositions of resistance to burning polymer composite materials with flame retardants based on magnesium hydroxide","authors":"K. A. Brekhova, I. D. Simonov-Emel'yanov, A. Pykhtin","doi":"10.32362/2410-6593-2023-18-2-109-122","DOIUrl":"https://doi.org/10.32362/2410-6593-2023-18-2-109-122","url":null,"abstract":"Objectives. To identify general principles for the design of dispersed-filled polymer composite materials (DFPCMs) with different generalized and reduced parameters, as well as types of disperse structure with high fire resistance; to develop an algorithm for the creation of non-combustible polymer composites with flame-retardant fillers.Methods. Scanning electron microscopy and laser diffraction were used to assess the shape, size, and particle size distribution of flame retardants. According to the presented classification of DFPCMs by structural principle, standard bar samples were obtained to determine the oxygen index (OI) and the fire resistance category.Results. For the MFS-2 (medium filled system) and HFS (high filled system) structure types, the maximum resistance to burning (category V-0) is achieved with a generalized parameter of ® ≤ 0.40 volume fractions; the OI value increases in 2 times (up to ~40%) in relation to the polymer matrix.Conclusions. In order to obtain a flame retardant DFPCMs (OI = 40%, category V-0) based on ethylene vinyl acetate with OI = 20% and magnesium hydroxide (brucite), the amount of water vapor released during the decomposition of the flame-retardant filler should be at least ~250 mL/g with a coke residue ~32%. A developed algorithm for calculating compositions and generalized parameters for the creation of DFPCMs having a predetermined type of disperse structure and high resistance to burning is presented.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75005829","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 : 2023-05-26DOI: 10.32362/2410-6593-2023-18-2-83-97
P. S. Klauzner, D. G. Rudakov, E. Anokhina, A. Timoshenko
Objectives. The study aims to investigate the effectiveness of the use of various options for organizing the process of diabatic distillation in the separation of a mixture of acetone-toluene-n-butanol by extractive distillation using dimethylformamide as an entrainer in a scheme with preliminary separation of azeotropic components.Methods. As the main research method, mathematical modeling in the Aspen Plus V. 12 software package was used. As a model for describing vapor-liquid equilibrium, the local composition Non-Random Two Liquid equation model was used. Parametric optimization of diabatic schemes was carried out according to the criterion of reduced energy costs.Results. Based on the scheme for extractive distillation of an acetone-toluene-n-butanol mixture with preliminary separation of azeotropic components, five options for organizing diabatic distillation schemes were considered, both with and without use of a compressor to reach a required flows temperature.Conclusion. It is shown that the use of diabatic schemes in the extractive distillation of a acetone-toluene-n-butanol mixture with dimethylformamide makes it possible to diminish the reduced energy costs by 8.9-43.5%. Meanwhile the maximum reduction in energy consumption is achieved in a scheme where upper vapor flows of two other columns are used to heat the azeotropic components separating column.
目标。本研究的目的是探讨在以二甲基甲酰胺为夹带剂的萃取精馏分离丙酮-甲苯-正丁醇混合物的过程中，在共沸组分初步分离的方案中，使用各种选择来组织非绝热精馏过程的有效性。主要研究方法是在Aspen Plus V. 12软件包中进行数学建模。作为描述汽液平衡的模型，采用了局部成分非随机双液方程模型。以降低能耗成本为准则，对非绝热方案进行了参数优化。以丙酮-甲苯-正丁醇混合液共沸组分初步分离的萃取精馏方案为基础，考虑了5种组织非绝热精馏方案的选择，包括使用和不使用压缩机以达到要求的流动温度。结果表明，在丙酮-甲苯-正丁醇混合物与二甲基甲酰胺的萃取精馏中，采用非绝热方案可使能耗降低8.9-43.5%。同时，采用另外两个塔的上部蒸汽流来加热共沸组分分离塔的方案，最大限度地降低了能耗。
{"title":"Application of diabatic extractive distillation schemes with preliminary separation of azeotropic components for separation of acetone-toluene-n-butanol mixture","authors":"P. S. Klauzner, D. G. Rudakov, E. Anokhina, A. Timoshenko","doi":"10.32362/2410-6593-2023-18-2-83-97","DOIUrl":"https://doi.org/10.32362/2410-6593-2023-18-2-83-97","url":null,"abstract":"Objectives. The study aims to investigate the effectiveness of the use of various options for organizing the process of diabatic distillation in the separation of a mixture of acetone-toluene-n-butanol by extractive distillation using dimethylformamide as an entrainer in a scheme with preliminary separation of azeotropic components.Methods. As the main research method, mathematical modeling in the Aspen Plus V. 12 software package was used. As a model for describing vapor-liquid equilibrium, the local composition Non-Random Two Liquid equation model was used. Parametric optimization of diabatic schemes was carried out according to the criterion of reduced energy costs.Results. Based on the scheme for extractive distillation of an acetone-toluene-n-butanol mixture with preliminary separation of azeotropic components, five options for organizing diabatic distillation schemes were considered, both with and without use of a compressor to reach a required flows temperature.Conclusion. It is shown that the use of diabatic schemes in the extractive distillation of a acetone-toluene-n-butanol mixture with dimethylformamide makes it possible to diminish the reduced energy costs by 8.9-43.5%. Meanwhile the maximum reduction in energy consumption is achieved in a scheme where upper vapor flows of two other columns are used to heat the azeotropic components separating column.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86586903","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 : 2023-03-20DOI: 10.32362/2410-6593-2023-18-1-65-74
P. Postnikov, F. V. Radus, Y. Efimova, I. Pronina
Objectives. Cobalt mimics the state of hypoxia to prevent degradation of the alpha subunit of hypoxia-inducible factor, resulting in an increase in blood oxygen capacity and endurance. Athletes can use this property to gain competitive advantage. Nowadays, direct methods of inductively coupled plasma mass spectrometry and liquid chromatography-tandem mass spectrometry are used to determine total cobalt levels in the body. However, the World Anti-Doping Agency is yet to establish a maximum allowable threshold concentration of this element in biofluids. The lack of clear identification criteria complicates the interpretation of the obtained results for the purposes of doping control. In this regard, the present work proposes a new approach for the indirect determination of possible cobalt abuse based on changes in the expression levels of miRNAs involved in the regulation of hypoxia signaling pathways. Here, the aim is to identify possible microRNA markers whose expression does not depend on exercise-induced hypoxia, but changes markedly when taking cobalt preparations.Methods. MicroRNA isolation was performed from blood plasma samples using the PAXgene Blood miRNA Kit. Quantitative real-time polymerase chain reaction (PCR) was performed on CFX96 Bio-Rad (USA) analyzer using miScript® SYBR® Green PCR Kits and panels for studying the expression profiles of mature microRNAs of the hypoxia signaling pathway miScript® miRNA PCR Array.Results. Based on the statistical analysis of the data, it was found that the expression of hsa-miR-15b-5p in the blood plasma of the subjects does not depend on physical activity, but increases when taking cobalt preparations.Conclusions. The difference in expression levels during anaerobic exercise-induced hypoxia and cobalt-induced hypoxia makes hsa-miR-15b-5p a potential candidate to be a marker of erythropoiesis-stimulating agent abuse.
{"title":"Determination of possible microRNA-markers of cobalt abuse by real-time qPCR using hypoxia signaling pathway panels","authors":"P. Postnikov, F. V. Radus, Y. Efimova, I. Pronina","doi":"10.32362/2410-6593-2023-18-1-65-74","DOIUrl":"https://doi.org/10.32362/2410-6593-2023-18-1-65-74","url":null,"abstract":"Objectives. Cobalt mimics the state of hypoxia to prevent degradation of the alpha subunit of hypoxia-inducible factor, resulting in an increase in blood oxygen capacity and endurance. Athletes can use this property to gain competitive advantage. Nowadays, direct methods of inductively coupled plasma mass spectrometry and liquid chromatography-tandem mass spectrometry are used to determine total cobalt levels in the body. However, the World Anti-Doping Agency is yet to establish a maximum allowable threshold concentration of this element in biofluids. The lack of clear identification criteria complicates the interpretation of the obtained results for the purposes of doping control. In this regard, the present work proposes a new approach for the indirect determination of possible cobalt abuse based on changes in the expression levels of miRNAs involved in the regulation of hypoxia signaling pathways. Here, the aim is to identify possible microRNA markers whose expression does not depend on exercise-induced hypoxia, but changes markedly when taking cobalt preparations.Methods. MicroRNA isolation was performed from blood plasma samples using the PAXgene Blood miRNA Kit. Quantitative real-time polymerase chain reaction (PCR) was performed on CFX96 Bio-Rad (USA) analyzer using miScript® SYBR® Green PCR Kits and panels for studying the expression profiles of mature microRNAs of the hypoxia signaling pathway miScript® miRNA PCR Array.Results. Based on the statistical analysis of the data, it was found that the expression of hsa-miR-15b-5p in the blood plasma of the subjects does not depend on physical activity, but increases when taking cobalt preparations.Conclusions. The difference in expression levels during anaerobic exercise-induced hypoxia and cobalt-induced hypoxia makes hsa-miR-15b-5p a potential candidate to be a marker of erythropoiesis-stimulating agent abuse.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90255933","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 : 2023-03-20DOI: 10.32362/2410-6593-2023-18-1-21-28
A. I. Musin, D. S. Sultanova, Y. Borisova, T. P. Mudrik, R. Daminev
Objectives. To synthesize tertiary amines containing gem-dichlorocyclopropane or 1,3-dioxolane fragmentusing the Mannich reaction, as well as obtain ethyl ester of β-aminopropionic acidbydecarboxylation of tert-amine, a derivative of diethylmalonate containing a gem- dichlorocyclopropane fragment.Methods. In order to obtain tertiary amines by the Mannich reaction, the microwave activation method was used. To determine the qualitative and quantitative composition of the reaction masses, gas chromatography, electron ionization mass spectrometry, and 1H-, 13C-nuclear magnetic resonance spectrometry methodswere used.Results. Under microwave radiationconditions, tertiary amines containing gem- dichlorocyclopropane or 1,3-dioxolane fragment were synthesized by condensation of secondary amines, CH-acids, and paraformaldehyde.Conclusions. Tertiary amines containing a gem-dichlorocyclopropane or cycloacetal fragment in their structure were obtainedin high yields under microwave radiation.
{"title":"Condensation of secondary amines with CH-acids and formaldehyde under the influence of microwave radiation","authors":"A. I. Musin, D. S. Sultanova, Y. Borisova, T. P. Mudrik, R. Daminev","doi":"10.32362/2410-6593-2023-18-1-21-28","DOIUrl":"https://doi.org/10.32362/2410-6593-2023-18-1-21-28","url":null,"abstract":"Objectives. To synthesize tertiary amines containing gem-dichlorocyclopropane or 1,3-dioxolane fragmentusing the Mannich reaction, as well as obtain ethyl ester of β-aminopropionic acidbydecarboxylation of tert-amine, a derivative of diethylmalonate containing a gem- dichlorocyclopropane fragment.Methods. In order to obtain tertiary amines by the Mannich reaction, the microwave activation method was used. To determine the qualitative and quantitative composition of the reaction masses, gas chromatography, electron ionization mass spectrometry, and 1H-, 13C-nuclear magnetic resonance spectrometry methodswere used.Results. Under microwave radiationconditions, tertiary amines containing gem- dichlorocyclopropane or 1,3-dioxolane fragment were synthesized by condensation of secondary amines, CH-acids, and paraformaldehyde.Conclusions. Tertiary amines containing a gem-dichlorocyclopropane or cycloacetal fragment in their structure were obtainedin high yields under microwave radiation.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78161550","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 : 2023-03-20DOI: 10.32362/2410-6593-2023-18-1-48-64
E. Sedova, D. N. Shcherbinin, A. S. Bandelyuk, L. V. Verkhovskaya, N. Viskova, E. D. Avdonina, V. V. Prokofiev, E. I. Ryabova, I. Esmagambetov, K. A. Pervoykina, E. Bogacheva, A. Lysenko, M. Shmarov
Objectives. To develop a technology for obtaining recombinant antibodies in a suspension culture of human HEK293 cells using transduction with recombinant adenovirus serotype 5 (rAd5) carrying genes expressing heavy and light chains of antibodies on the example of two broadspectrum anti-influenza antibodies 27F3 and CR9114.Methods. Ad5-27F3-H, Ad5-CR9114-H, and Ad5-27F3-L recombinant adenoviruses carrying the 27F3 antibody heavy chain gene, CR9114 antibody heavy chain gene, and 27F3 light chain gene, respectively, were generated using the AdEasy™ Adenoviral vector system. To accumulate preparative amounts of recombinant r27F3 and rCR9114 antibodies, the HEK293 suspension cell line was transduced with recombinant adenoviruses carrying genes for heavy and light chains of antibodies. The cells were cultured in a wave-type bioreactor. Chromatography was used to purify recombinant antibodies from the culture medium. After analyzing the molecular weights of purified antibodies using protein electrophoresis, their ability to interact with influenza A and B viruses was analyzed using the Western blot technique, while their ability to neutralize influenza A and B viruses was evaluated using the virus neutralization assay.Results. A method for the accumulation and purification of recombinant r27F3 and CR9114 antibodies from the culture medium of a suspension culture of human cells following transduction with its recombinant adenoviruses carrying the genes for heavy and light chains of these antibodies was developed. The ability of the r27F3 antibody to interact with and neutralize influenza A viruses of group 1 (except influenza A virus subtype H2) and group 2 was shown. The ability of the rCR9114 antibody to interact with influenza A viruses of group 1 and influenza B viruses, as well as to neutralize influenza A viruses of group 1, was demonstrated.Conclusions. A technology for obtaining recombinant antibodies in a suspension culture of HEK293 cells using transduction with recombinant adenoviruses carrying genes expressing heavy and light chains of antibodies was developed along with a confirmation of their specificity.
{"title":"Method for obtaining recombinant antibodies produced by a cell line transduced with recombinant adenoviruses","authors":"E. Sedova, D. N. Shcherbinin, A. S. Bandelyuk, L. V. Verkhovskaya, N. Viskova, E. D. Avdonina, V. V. Prokofiev, E. I. Ryabova, I. Esmagambetov, K. A. Pervoykina, E. Bogacheva, A. Lysenko, M. Shmarov","doi":"10.32362/2410-6593-2023-18-1-48-64","DOIUrl":"https://doi.org/10.32362/2410-6593-2023-18-1-48-64","url":null,"abstract":"Objectives. To develop a technology for obtaining recombinant antibodies in a suspension culture of human HEK293 cells using transduction with recombinant adenovirus serotype 5 (rAd5) carrying genes expressing heavy and light chains of antibodies on the example of two broadspectrum anti-influenza antibodies 27F3 and CR9114.Methods. Ad5-27F3-H, Ad5-CR9114-H, and Ad5-27F3-L recombinant adenoviruses carrying the 27F3 antibody heavy chain gene, CR9114 antibody heavy chain gene, and 27F3 light chain gene, respectively, were generated using the AdEasy™ Adenoviral vector system. To accumulate preparative amounts of recombinant r27F3 and rCR9114 antibodies, the HEK293 suspension cell line was transduced with recombinant adenoviruses carrying genes for heavy and light chains of antibodies. The cells were cultured in a wave-type bioreactor. Chromatography was used to purify recombinant antibodies from the culture medium. After analyzing the molecular weights of purified antibodies using protein electrophoresis, their ability to interact with influenza A and B viruses was analyzed using the Western blot technique, while their ability to neutralize influenza A and B viruses was evaluated using the virus neutralization assay.Results. A method for the accumulation and purification of recombinant r27F3 and CR9114 antibodies from the culture medium of a suspension culture of human cells following transduction with its recombinant adenoviruses carrying the genes for heavy and light chains of these antibodies was developed. The ability of the r27F3 antibody to interact with and neutralize influenza A viruses of group 1 (except influenza A virus subtype H2) and group 2 was shown. The ability of the rCR9114 antibody to interact with influenza A viruses of group 1 and influenza B viruses, as well as to neutralize influenza A viruses of group 1, was demonstrated.Conclusions. A technology for obtaining recombinant antibodies in a suspension culture of HEK293 cells using transduction with recombinant adenoviruses carrying genes expressing heavy and light chains of antibodies was developed along with a confirmation of their specificity.","PeriodicalId":12215,"journal":{"name":"Fine Chemical Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83563710","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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