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.

Objectives. To develop a methodology for the quantitative assessment of new technologies in accordance with the principles of best available technologies (BAT). To evaluate the developed technologies of low-tonnage chemical production of tetramethylthiuram disulfide, N-cyclohexyl-2- benzothiazolylsulfenamide, diisopropyl xanthohen disulfide, and N-phenyl-2-naphthylamine for compliance with BAT principles and compare with alternative (implemented, known) technologies in terms of environmental impact.

Methods. A methodology for the quantitative assessment of new technologies for the production of organic substances in accordance with BAT principles was used.

Results. The developed methodology for the quantitative assessment of new technologies in accordance with BAT principles based on the calculation of comprehensive comparison indicators with alternative technologies for technological and environmental indicators allowed us to determine the level of implemented technologies for the production of tetramethylthiuram disulfide, N-cyclohexyl-2-benzothiazolylsulfenamide, diisopropyl xanthohen disulfide, and N-phenyl-2- naphthylamine to minimize the impact on the environmental, including through the development of special technological solutions for resource conservation and waste reduction, and to conduct a quantitative assessment of the achieved environmental outcome. It is established that the considered new technologies of low-tonnage chemical production comply with BAT principles and are more environmentally advanced compared to alternative ones previously implemented in the USSR.

Conclusions. For the first time, a methodology for quantifying new technologies in accordance with BAT principles is proposed. The possibility of its use at the stage of making basic technological decisions on the implemented production method in order to ensure compliance with legislative requirements for technologies in the field of environmental safety to achieve environmental protection goals is shown on the example of low-tonnage technologies for the production of tetramethylthiuram disulfide, N-cyclohexyl-2-benzothiazolylsulfenamide, diisopropyl xanthohen disulfide, and N-phenyl-2-naphthylamine created in GosNIIOKhT.

Objectives. To develop the procedures for synthesis of hybrid molecules with potential anti-tubercular activity containing heterocyclic cores of 4-nitroimidazole and 1,3,4-thiadiazole within the framework of a double-drug strategy and predict bioactivity of target structures and drug-likeness physicochemical parameters.

Methods. Target compounds were prepared by classical organic synthesis methods. The structure of the obtained compounds was characterized by melting points, ¹H and ¹³C nuclear magnetic resonance spectroscopy, and high-resolution mass spectrometry. The calculation of the physicochemical parameters of the target compounds and prediction of their biological activity were carried out using publicly available software for cheminformatics and molecular modeling.

Results. Acylation of propargylamine with (2-methyl-4-nitro-1H-imidazol-1-yl)acetic and (4-nitro-1H-imidazol-1-yl)acetic acids provided the corresponding amides, which were cyclized with seven different benzylamines in the presence of zinc triflate. In this way, seven new compounds were obtained at 20–30% yields. Ten arylamines were acylated with chloroacetyl chloride and the resulting chloroacetamides were converted into corresponding thio-oxahydrazides by the Willgerodt–Kindler reaction. Following acylation by (4-nitro-1H-imidazol-1-yl)acetic acid, these compounds were converted into the target hybrid imidazolyl-thiadiazoles at 29–54% yields.

Conclusions. Two series of new heterocyclic compounds with a hybrid structure including a privileged 4-nitroimidazole moiety linked to the second heterocycle, imidazole, or thiadiazole, were obtained. The synthesis and characterization of compounds by physicochemical methods was aimed at searching for anti-tuberculosis activity. The bioactivity potential of target compounds was demonstrated by preliminary calculations performed using public prognostic programs.

Objectives. To conduct a comparative analysis of the features of a fermentation unit design for obtaining bioprotein from natural gas and determine the main technical and structural solutions used in the development of fermentation apparatus, which vary according to the method of organizing hydraulic and mass transfer processes.

Results. An analysis of publications devoted to the problem of developing technological equipment for conducting the process of obtaining a bioprotein from natural gas is presented. Using the comparative analysis, the key features of bioreactors and their internal elements are indicated according to the method of organizing the hydrodynamic regime. The main approaches to the technological development of fermentation units for obtaining bioprotein from natural gas are described and technical solutions used in the implementation of these structures are identified.

Conclusions. Fermenter designs for the cultivation of methane-oxidizing microorganisms vary according to the main approaches for implementing the hydraulic regime inside the apparatus. While one class of fermentation systems is based on the principle of volumetric mixing in the working space of the apparatus, with the possibility of including external circulation circuits, additional tanks, and auxiliary bioreactors in the system, the other main class relies on the principle of flow (displacement) in the tube space with subsequent release of the gas phase from the circulating culture liquid.

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.

Objectives. To develop a method for the determination of hypochlorite, chloride, chlorite, chlorate, and perchlorate ions in solution; to determine the limits of detection and quantitation for ClO−, Cl−, ClO₂−, ClO₃−, and ClO₄− ions; to evaluate the applicability of the developed method and its suitability for disinfectant analysis.

Methods. Ionic chromatography using a conductometric detection system in isocratic elution mode.

Results. The method developed for chromatographic determination of chlorine-containing ions can be used to quantify the content of hypochlorite, chloride, chlorite, chlorate, and perchlorate ions. In isocratic elution mode at 7.5 mM NaOH and a flow rate of 0.4 mL/min, the content of chlorine-containing ions can be determined with high sensitivity. The presented method does not require the use of expensive equipment for the ultrasensitive analysis of the studied compounds.

Conclusions. A novel method for the simultaneous determination of hypochlorite, chloride, chlorite, chlorate, and perchlorate ions in case of their combined presence is proposed. The technique can be used to carry out routine control of the content of these disinfectant components during use, increasing their effectiveness at the same time as managing associated toxicological risks.

Objectives. The study set out to use mathematical modeling, in particular the method of multifactorial analysis of multicriteria optimization (MAMO), in the development of a pharmaceutical product.

Methods. After carrying out experimental tests based on the proposed algorithmic sequence, the obtained data were interpreted using MAMO.

Results. The possibility of using MAMO to solve the applied problem of purifying oligohexamethyleneguanidine hydrosuccinate (OHMG-HS), considered as a pharmaceutical precursor for the creation of medicines, was demonstrated.

Conclusions. The expediency of using the proposed algorithm as a tool for pharmaceutical development is substantiated by identifying dependencies of the influence of purification conditions on the final content of admixtures in the target product.