Pub Date : 2023-12-02DOI: 10.29235/1561-8331-2023-59-4-341-352
R. Popov, F. I. Pantsialeyenka, E. Dyatlova, V. Biryuk, O. P. Moh, I. R. Hula, H. M. Shymanskaya, A. S. Samsonava
The article considers chemical, mineralogical and granulometric features of clay raw materials from the "Krupeisky Sad" deposit, presents its technological and color properties. The thermal transformation of clays under firing conditions were studied. It was revealed that clays from the "Krupeisky Sad" deposit were characterized by a high content montmorillonite and fine-grained quartz, which had a negative impact on the technological effectiveness of the process of manufacturing ceramic products. Compositions, including clay raw materials from the "Krupeysky Sad" deposit, quartz sand or granite screenings, burnout additive, as well as a technology for producing ceramic bricks, were developed. It had been established that it is advisable to use granite screenings, because it provides higher strength characteristics of products due to the peculiarities of the mineralogical composition and the shape of the grains. In addition, the optimal content of sawdust (not more than 3.5 wt.%), which allowed to intensify the processes of drying and firing of the material, was determined. The technical and economic efficiency of the developed compositions and technological modes to obtain ceramic bricks were confirmed by test in the conditions of the Production Unitary Enterprise "Loyevsky Combine of Building Materials" JSC "Polesestroy".
{"title":"Application features of clay raw materials from the \"Krupeisky sad\" deposit for obtaining ceramic building material","authors":"R. Popov, F. I. Pantsialeyenka, E. Dyatlova, V. Biryuk, O. P. Moh, I. R. Hula, H. M. Shymanskaya, A. S. Samsonava","doi":"10.29235/1561-8331-2023-59-4-341-352","DOIUrl":"https://doi.org/10.29235/1561-8331-2023-59-4-341-352","url":null,"abstract":"The article considers chemical, mineralogical and granulometric features of clay raw materials from the \"Krupeisky Sad\" deposit, presents its technological and color properties. The thermal transformation of clays under firing conditions were studied. It was revealed that clays from the \"Krupeisky Sad\" deposit were characterized by a high content montmorillonite and fine-grained quartz, which had a negative impact on the technological effectiveness of the process of manufacturing ceramic products. Compositions, including clay raw materials from the \"Krupeysky Sad\" deposit, quartz sand or granite screenings, burnout additive, as well as a technology for producing ceramic bricks, were developed. It had been established that it is advisable to use granite screenings, because it provides higher strength characteristics of products due to the peculiarities of the mineralogical composition and the shape of the grains. In addition, the optimal content of sawdust (not more than 3.5 wt.%), which allowed to intensify the processes of drying and firing of the material, was determined. The technical and economic efficiency of the developed compositions and technological modes to obtain ceramic bricks were confirmed by test in the conditions of the Production Unitary Enterprise \"Loyevsky Combine of Building Materials\" JSC \"Polesestroy\".","PeriodicalId":20798,"journal":{"name":"Proceedings of the National Academy of Sciences of Belarus, Chemical Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138607432","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 : 2023-12-02DOI: 10.29235/1561-8331-2023-59-4-285-294
V. D. Koshevar, V. G. Shkadretsova, A. S. Pismenskaya
Lamellar microparticles of talc modified with surfactants of anionic (LEUKONOL LBA-2) and cationic (al- kyldimethylamine N-oxide) types were used as a solid stabilizer of the Pickering emulsion of the 2nd kind (water/oil) of the epoxy oligomer. The microstructure of this emulsion, in contrast to that obtained using an unmodified mineral as a stabilizer, is characterized by significant polydispersity, the presence of a higher concentration of drops of 0.08–1 microns in size, as well as the presence of a larger number of colloidosomes with a diameter of 4–30 microns. The good stability of this emulsion is due to the simultaneous formation of a dispersed phase from droplets with a diameter of 0.02–0.04 microns, which have an additional stabilizing effect on it. Such structural differences led to a higher degree of chemical hardening of the emulsion and the formation of coatings with homogeneous morphology and increased physical and mechanical characteristics, which opens up prospects for its use as film-forming agents in the creation of flame-retardant paint materials.
{"title":"Pickering emulsions of epoxy oligomer stabilized by modified talc microparticles and their properties","authors":"V. D. Koshevar, V. G. Shkadretsova, A. S. Pismenskaya","doi":"10.29235/1561-8331-2023-59-4-285-294","DOIUrl":"https://doi.org/10.29235/1561-8331-2023-59-4-285-294","url":null,"abstract":"Lamellar microparticles of talc modified with surfactants of anionic (LEUKONOL LBA-2) and cationic (al- kyldimethylamine N-oxide) types were used as a solid stabilizer of the Pickering emulsion of the 2nd kind (water/oil) of the epoxy oligomer. The microstructure of this emulsion, in contrast to that obtained using an unmodified mineral as a stabilizer, is characterized by significant polydispersity, the presence of a higher concentration of drops of 0.08–1 microns in size, as well as the presence of a larger number of colloidosomes with a diameter of 4–30 microns. The good stability of this emulsion is due to the simultaneous formation of a dispersed phase from droplets with a diameter of 0.02–0.04 microns, which have an additional stabilizing effect on it. Such structural differences led to a higher degree of chemical hardening of the emulsion and the formation of coatings with homogeneous morphology and increased physical and mechanical characteristics, which opens up prospects for its use as film-forming agents in the creation of flame-retardant paint materials.","PeriodicalId":20798,"journal":{"name":"Proceedings of the National Academy of Sciences of Belarus, Chemical Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138607730","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 : 2023-12-02DOI: 10.29235/1561-8331-2023-59-4-295-301
T. N. Bochko, Ju. P. Dubovik, Iu. A. Savelieva
The paper presents the results of determining the component composition and identifying substances of artificial origin in the samples of lavender essential oil Lavandula spp. by gas chromatography-mass spectrometry and refractometry. The analysis of biologically active substances in lavender essential oils was carried out, the isolated components of the oils were screened for the limit of permissible concentrations and their chemical nature according to GOST, the refractive indices were determined.
{"title":"Determination of component composition of lavender es- sential oils Lavandula spp.","authors":"T. N. Bochko, Ju. P. Dubovik, Iu. A. Savelieva","doi":"10.29235/1561-8331-2023-59-4-295-301","DOIUrl":"https://doi.org/10.29235/1561-8331-2023-59-4-295-301","url":null,"abstract":"The paper presents the results of determining the component composition and identifying substances of artificial origin in the samples of lavender essential oil Lavandula spp. by gas chromatography-mass spectrometry and refractometry. The analysis of biologically active substances in lavender essential oils was carried out, the isolated components of the oils were screened for the limit of permissible concentrations and their chemical nature according to GOST, the refractive indices were determined.","PeriodicalId":20798,"journal":{"name":"Proceedings of the National Academy of Sciences of Belarus, Chemical Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138606160","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 : 2023-12-02DOI: 10.29235/1561-8331-2023-59-4-271-284
O. Kulakovich, P. D. Raetsky, O. V. Vershinina, L. L. Trotsyuk
A new mixed reduction system for the synthesis of gold nanorods (NRs), including ascorbic acid and hydro- quinone, has been proposed. Dependence of NRs longitudinal plasmon resonance band position on the concentration of silver ions, ascorbic acid and hydroquinone during synthesis were found, which makes it possible to obtain NRs with required op- tical properties. It was found that when using a mixed reducing agent, higher monodispersity and morphological yield can be achieved as compared to individual reducing agents, which is especially important for obtaining short NRs with a maximum of longitudinal plasmon resonance in the region of 600–700 nm.
{"title":"Synthesis of gold nanorods using a mixed reducing agent hydroquinone–ascorbic acid","authors":"O. Kulakovich, P. D. Raetsky, O. V. Vershinina, L. L. Trotsyuk","doi":"10.29235/1561-8331-2023-59-4-271-284","DOIUrl":"https://doi.org/10.29235/1561-8331-2023-59-4-271-284","url":null,"abstract":"A new mixed reduction system for the synthesis of gold nanorods (NRs), including ascorbic acid and hydro- quinone, has been proposed. Dependence of NRs longitudinal plasmon resonance band position on the concentration of silver ions, ascorbic acid and hydroquinone during synthesis were found, which makes it possible to obtain NRs with required op- tical properties. It was found that when using a mixed reducing agent, higher monodispersity and morphological yield can be achieved as compared to individual reducing agents, which is especially important for obtaining short NRs with a maximum of longitudinal plasmon resonance in the region of 600–700 nm.","PeriodicalId":20798,"journal":{"name":"Proceedings of the National Academy of Sciences of Belarus, Chemical Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138607316","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 : 2023-12-02DOI: 10.29235/1561-8331-2023-59-4-302-311
S. Leschev, Y. Pakhadnia, O. N. Tchekhovskaya, A. A. Ahabalayeu, M. Zayats
The extraction of anabolic steroids (testosterone; epitestosterone; epimethenediol; 17α-methyltestosterone; 19-norethiocholanolone; 18-normethenol; 19-norandrosterone; 3α-hydroxy-2α-methyl-5α-androstan-17-one; 9α-fluoro-17,17dimethyl-18-norandrostan-4,13-dien-11β-ol-3-one; 1α-methyl-5α-androstan-3α-ol-17-one; 1α-methyl-5αandrostan-3α,17β-diol; epioxandrolone; methasterone; oxandrolone; formestane; 16β-hydroxyfurazabol) with organic solvents from water and aqueous salt solutions was studied at 20 ° C. Based on the experimental data obtained, the partition ratios of anabolic steroids (AS) were calculated, which were used to optimize the standard sample preparation procedure in the process of determining anabolic androgenic steroids (AAS) and their metabolites in the urine of athletes. It was found that the most selective extractant from aqueous and aqueous salt solutions is hexane, which extracts the majority of AAS. To increase the recovery of AAS, poorly extracted by hexane, it is advisable to use salting out with sodium or ammonium sulfate and use more active organic extractants – methylene chloride or diethyl ether. An extraction sample preparation technique has been developed for the subsequent determination of anabolic steroids and their metabolites in athletes’ urine by gas chromatography with mass spectrometric detection method. The proposed method is characterized by a standard deviation of 10 – 15 % and a detection limit of about 10 ng/ml of urine.
{"title":"Organic solvent extraction of anabolic steroids from aqueous solutions","authors":"S. Leschev, Y. Pakhadnia, O. N. Tchekhovskaya, A. A. Ahabalayeu, M. Zayats","doi":"10.29235/1561-8331-2023-59-4-302-311","DOIUrl":"https://doi.org/10.29235/1561-8331-2023-59-4-302-311","url":null,"abstract":"The extraction of anabolic steroids (testosterone; epitestosterone; epimethenediol; 17α-methyltestosterone; 19-norethiocholanolone; 18-normethenol; 19-norandrosterone; 3α-hydroxy-2α-methyl-5α-androstan-17-one; 9α-fluoro-17,17dimethyl-18-norandrostan-4,13-dien-11β-ol-3-one; 1α-methyl-5α-androstan-3α-ol-17-one; 1α-methyl-5αandrostan-3α,17β-diol; epioxandrolone; methasterone; oxandrolone; formestane; 16β-hydroxyfurazabol) with organic solvents from water and aqueous salt solutions was studied at 20 ° C. Based on the experimental data obtained, the partition ratios of anabolic steroids (AS) were calculated, which were used to optimize the standard sample preparation procedure in the process of determining anabolic androgenic steroids (AAS) and their metabolites in the urine of athletes. It was found that the most selective extractant from aqueous and aqueous salt solutions is hexane, which extracts the majority of AAS. To increase the recovery of AAS, poorly extracted by hexane, it is advisable to use salting out with sodium or ammonium sulfate and use more active organic extractants – methylene chloride or diethyl ether. An extraction sample preparation technique has been developed for the subsequent determination of anabolic steroids and their metabolites in athletes’ urine by gas chromatography with mass spectrometric detection method. The proposed method is characterized by a standard deviation of 10 – 15 % and a detection limit of about 10 ng/ml of urine.","PeriodicalId":20798,"journal":{"name":"Proceedings of the National Academy of Sciences of Belarus, Chemical Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138606836","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 : 2023-12-02DOI: 10.29235/1561-8331-2023-59-4-312-317
E. Dikusar, A. Pushkarchuk, T. V. Bezyazychnaya, E. A. Akishina, E. Kasandrovich, A. Soldatov, S. Kuten, S. Stepin, A. Nizovtsev, S. Kilin, V. A. Kulchitsky, V. Potkin
Tetraeicosahydroxyfullerene C60(OH)24 has a wide range of unique and useful properties that allow it to be successfully used in a number of sectors of the national economy. Interest in this compound is due to its extremely high biological potential, which manifests itself in a potentiating effect against malignant neoplasms (when used together with cisplatin) and as an agent for the delivery of radioactive isotopes in radiation medicine. This paper presents a convenient and easily scalable procedure for the synthesis and purification of C60(OH)24 tetraeicosahydroxyfullerene by catalytic bromination of C60 fullerene in liquid bromine in the presence of metallic iron. The technology of purification of the target product using ion exchange resins AB-17-8 and TOKEM-100 has been developed.
{"title":"Tetraeicosahydroxyfullerene C60(ОН)24: optimized preparative synthesis, properties and applica-tions","authors":"E. Dikusar, A. Pushkarchuk, T. V. Bezyazychnaya, E. A. Akishina, E. Kasandrovich, A. Soldatov, S. Kuten, S. Stepin, A. Nizovtsev, S. Kilin, V. A. Kulchitsky, V. Potkin","doi":"10.29235/1561-8331-2023-59-4-312-317","DOIUrl":"https://doi.org/10.29235/1561-8331-2023-59-4-312-317","url":null,"abstract":"Tetraeicosahydroxyfullerene C60(OH)24 has a wide range of unique and useful properties that allow it to be successfully used in a number of sectors of the national economy. Interest in this compound is due to its extremely high biological potential, which manifests itself in a potentiating effect against malignant neoplasms (when used together with cisplatin) and as an agent for the delivery of radioactive isotopes in radiation medicine. This paper presents a convenient and easily scalable procedure for the synthesis and purification of C60(OH)24 tetraeicosahydroxyfullerene by catalytic bromination of C60 fullerene in liquid bromine in the presence of metallic iron. The technology of purification of the target product using ion exchange resins AB-17-8 and TOKEM-100 has been developed.","PeriodicalId":20798,"journal":{"name":"Proceedings of the National Academy of Sciences of Belarus, Chemical Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138606428","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 : 2023-12-02DOI: 10.29235/1561-8331-2023-59-4-318-333
S. V. Vasilevich, E. A. Shaporova, S. О. Stoyko
The paper discusses the results of a kinetic study of the thermal decomposition of MS-8P, TN-98, and TN-600 aviation oils under conditions of continuous heating at a constant rate of 5 K/min to a temperature of 1 073 K. An integral method was used to describe the reaction mechanism and determine the macrokinetic parameters. It has been established that, from a phenomenological point of view, the average reaction of aviation oils conversion under the experimental conditions corresponds to the reaction model described by the surface-limited reaction equation (MS-8P), the power law (TN-98) and the model described by the three-dimensional diffusion-limited reaction equation (TN-600). When dividing the averaged reaction into two reactions (the first is completed at a temperature of 550–600 K, the second at a temperature of 638–655 K), it is determined that the first reaction is described by the reaction equation of the 2nd order (MS-8P), the first order (TN-98) and the reaction equation of one-dimensional diffusion (TN-600), and the second the reaction equation of the first order (three types of oil). The activation energy of the first reaction was 99 kJ/mol (MS-8P), 145.6 kJ/mol (TN-98) and 57.4 kJ/mol (TN-600), the value of the pre-exponential factor was – 144 241 567 min–1 (MS-8P), 62 161 395 942 min–1 (TN-98) and 236.16 min–1 (TN600). The activation energy of the second reaction is 160 kJ/mol (MS-8P), 91.6 kJ/mol (TN-98) and 127.1 kJ/mol (TN-600), the pre-exponential factor is 8.81 ‧ 1011 min–1 (MS-8P), 1.26 ‧ 104 min–1 (TN-98) and 2.04 ‧ 108 min–1 (TN-600). It is shown that the use of these values of the activation energy and the pre-exponential factor leads to agreement between the calculated values of the degree of decomposition of the studied oil samples and the experimental ones in the range of values of the degree of decomposition from 0 to 1.
{"title":"Study of the kinetics of aviation oils thermal conversion under non-isothermal conditions","authors":"S. V. Vasilevich, E. A. Shaporova, S. О. Stoyko","doi":"10.29235/1561-8331-2023-59-4-318-333","DOIUrl":"https://doi.org/10.29235/1561-8331-2023-59-4-318-333","url":null,"abstract":"The paper discusses the results of a kinetic study of the thermal decomposition of MS-8P, TN-98, and TN-600 aviation oils under conditions of continuous heating at a constant rate of 5 K/min to a temperature of 1 073 K. An integral method was used to describe the reaction mechanism and determine the macrokinetic parameters. It has been established that, from a phenomenological point of view, the average reaction of aviation oils conversion under the experimental conditions corresponds to the reaction model described by the surface-limited reaction equation (MS-8P), the power law (TN-98) and the model described by the three-dimensional diffusion-limited reaction equation (TN-600). When dividing the averaged reaction into two reactions (the first is completed at a temperature of 550–600 K, the second at a temperature of 638–655 K), it is determined that the first reaction is described by the reaction equation of the 2nd order (MS-8P), the first order (TN-98) and the reaction equation of one-dimensional diffusion (TN-600), and the second the reaction equation of the first order (three types of oil). The activation energy of the first reaction was 99 kJ/mol (MS-8P), 145.6 kJ/mol (TN-98) and 57.4 kJ/mol (TN-600), the value of the pre-exponential factor was – 144 241 567 min–1 (MS-8P), 62 161 395 942 min–1 (TN-98) and 236.16 min–1 (TN600). The activation energy of the second reaction is 160 kJ/mol (MS-8P), 91.6 kJ/mol (TN-98) and 127.1 kJ/mol (TN-600), the pre-exponential factor is 8.81 ‧ 1011 min–1 (MS-8P), 1.26 ‧ 104 min–1 (TN-98) and 2.04 ‧ 108 min–1 (TN-600). It is shown that the use of these values of the activation energy and the pre-exponential factor leads to agreement between the calculated values of the degree of decomposition of the studied oil samples and the experimental ones in the range of values of the degree of decomposition from 0 to 1.","PeriodicalId":20798,"journal":{"name":"Proceedings of the National Academy of Sciences of Belarus, Chemical Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138607211","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 : 2023-09-05DOI: 10.29235/1561-8331-2023-59-3-257-264
V. Fleisher, N. Chornaya
The modification of rosin resin acids, which improves their hydrophobic effect on paper and cardboard, is based on the implementation of 6 stages. Control of chemical processes at each stage is carried out by monitoring and regulating temperature and flow parameters, which determine the achievement of the required physical and chemical properties and composition of intermediates and final substance. One of the main indicators is the acid number, which for the final substance should be 60–70 mg KOH/g, which corresponds to the content of free resin acids in the functional substance of 40–45 %. The fulfillment of the specified temperature and consumption parameters for the modification of resin acids of rosin and the achievement of the necessary physicochemical properties of intermediates at each stage ensures the production of a functional substance with an improved hydrophobic effect on paper and cardboard. Compared to the traditionally used TM adhesive-paste, the developed functional substance in the production of paper with absorbency at one-sided wetting of not more than 21 g/m2 provides a reduction in the content of particles of the dispersed phase of the rosin emulsion by 1.4–2.0 times, which indicates its improved properties, and maximum preservation of the original strength of the paper by reducing the distance between the fibers due to a 3.3–3.8 times reduction (from 4200–5000 to 1100–1480 nm) in the size of sizing complexes.
{"title":"Modification of rosin resin acids to improve their hydrophobizing action on paper and cardboard","authors":"V. Fleisher, N. Chornaya","doi":"10.29235/1561-8331-2023-59-3-257-264","DOIUrl":"https://doi.org/10.29235/1561-8331-2023-59-3-257-264","url":null,"abstract":"The modification of rosin resin acids, which improves their hydrophobic effect on paper and cardboard, is based on the implementation of 6 stages. Control of chemical processes at each stage is carried out by monitoring and regulating temperature and flow parameters, which determine the achievement of the required physical and chemical properties and composition of intermediates and final substance. One of the main indicators is the acid number, which for the final substance should be 60–70 mg KOH/g, which corresponds to the content of free resin acids in the functional substance of 40–45 %. The fulfillment of the specified temperature and consumption parameters for the modification of resin acids of rosin and the achievement of the necessary physicochemical properties of intermediates at each stage ensures the production of a functional substance with an improved hydrophobic effect on paper and cardboard. Compared to the traditionally used TM adhesive-paste, the developed functional substance in the production of paper with absorbency at one-sided wetting of not more than 21 g/m2 provides a reduction in the content of particles of the dispersed phase of the rosin emulsion by 1.4–2.0 times, which indicates its improved properties, and maximum preservation of the original strength of the paper by reducing the distance between the fibers due to a 3.3–3.8 times reduction (from 4200–5000 to 1100–1480 nm) in the size of sizing complexes.","PeriodicalId":20798,"journal":{"name":"Proceedings of the National Academy of Sciences of Belarus, Chemical Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86833359","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 : 2023-09-04DOI: 10.29235/1561-8331-2023-59-3-202-210
V. Khripach, V. Zhabinskii, E. V. Sikorov, S. I. Lazarev
The synthesis of previously undescribed 22- and 23-deoxyanalogues of homocastasterone has been carried out, which makes it possible to obtain target compounds without replacing the carbon skeleton of the side chain. The key reactions in their synthesis were epoxy ring opening and radical debromination.
{"title":"Synthesis of 22- and 23-dehydroxybrassinosteroids of the stigmastane series","authors":"V. Khripach, V. Zhabinskii, E. V. Sikorov, S. I. Lazarev","doi":"10.29235/1561-8331-2023-59-3-202-210","DOIUrl":"https://doi.org/10.29235/1561-8331-2023-59-3-202-210","url":null,"abstract":"The synthesis of previously undescribed 22- and 23-deoxyanalogues of homocastasterone has been carried out, which makes it possible to obtain target compounds without replacing the carbon skeleton of the side chain. The key reactions in their synthesis were epoxy ring opening and radical debromination.","PeriodicalId":20798,"journal":{"name":"Proceedings of the National Academy of Sciences of Belarus, Chemical Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83925416","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 : 2023-09-04DOI: 10.29235/1561-8331-2023-59-3-234-241
A. A. Khiliuta, Y. V. Hryniuk
The objects of study were the process of frontal copolymerization of acrylamide with sodium acrylate in aqueous solutions in tubular reactors of various diameters and with different directions of front propagation, as well as the resulting copolymers and hydrogels. The effect of the diameter of a tubular reactor and the direction of front propagation on the process of frontal copolymerization of acrylamide and sodium acrylate in aqueous solutions has been studied. It was shown that the front velocity is almost independent of the diameter of the tubular reactor, and the front temperature decreases with increasing diameter. The values of water absorption and gel-fraction of the obtained hydrogels were determined.
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