Objectives. The aim of this study is to investigate different distillation modes of a binary ideal mixture and determine how various factors affect heat consumption in the column boilers. In addition, it intends to assess the difficulty of separating mixtures. Our research is based on analyzing the characteristics of vapor-liquid equilibrium.

Methods. To conduct our study, we used a graphic-analytical tool to calculate the distillation process of a binary mixture and mathematical models based on the Aspen Plus software package along with DSTWU, RadFrac, and the Sensitivity module. We also used the Peng-Robinson equation (PENG-ROB) to determine the liquid-vapor equilibrium.

Results. We employed the graphical method and mathematical models to obtain the operation parameters of two column variants for the distillation of binary ideal benzene-toluene mixtures. In each variant the initial mixture contained the same amount of the low- and high-boiling component. The number of plates in the column sections, reflux ratio, energy consumption, and indicators of internal energy saving were determined.

Conclusions. Study results show that using the coefficient of the component distribution between the vapor and liquid phases is a promising method for preliminary assessments of the separation difficulty and measurements of the expected heat consumption in the boilers of columns. Comparison studies showed that the heat consumption in the boiler decreases as the internal energy saving in the columns increases.

Objectives. Polymeric carbonate siloxanes containing a siloxane-N-phthalimidine group in the chain frame are new synthetic comb-like macromolecule systems. This work aims to study the possibility of applying them in the form of film materials for heat-resistant, high-performance gas-permeable membranes.

Methods. Comb-like polycarbonate siloxanes of the siloxane-containing polyether class were obtained using various polycondensation methods. i.e., by the polymer-analogous transformation of polycarbonate-allyl-N-phthalimidines, using their reaction in an alkyl hydride siloxane solution; polycondensation of N-(3-(pentamethyldisiloxane)-propyl)-3,3-bis-(4'-hydroxyphenyl)phthalimidine with diphenylolpropane bis-chloroformate in a solution using triethylamine as an acceptor of hydrochloric acid; interphase polycondensation of the above reagents in a dichloromethane aqueous alkali system. The structures of the obtained initial and polymeric compounds were confirmed by proton nuclear magnetic resonance spectroscopy and elemental analysis. All of the synthesized comb-like copolymers had good solubility in several available solvents and film formations.

Results. The new comb-like polycarbonate siloxanes had high thermal stability. According to thermogravimetric analysis, the introduction of up to 20 wt % siloxane units makes it possible to increase the heat resistance of polycarbonate siloxanes by 25 °C. Concurrently, their glasstransition temperature reaches 160 °C. Copolymers of polycarbonate siloxanes in the form of films have a high tensile strength above 50 MPa and an elastic modulus of up to 2000 MPa. The permeability coefficients of gases through a copolymer of polycarbonate siloxanes in the form of a film for several gases surpass the permeability of industrial polycarbonate from diphenylolpropane and fluorine-containing siloxane polycarbonate.

Conclusions. The results achieved indicate the possibility of creating new polymeric combshaped siloxane systems with a variable structure that can contribute to obtaining the properties desired from them. Combined with high selectivity gas separation, this makes it possible to use such comb-shaped polycarbonate siloxanes as film membrane materials with an increased operating temperature range.

Objectives. This study describes a new approach to obtain para-tert-butylcumene by alkylation of cumene with isobutylene in the presence of catalysts, such as Amberlyst 36 Dry, KU-2-8, aluminum chloride, and tert-butyl alcohol and concentrated sulfuric acid.

Methods. To determine the qualitative and quantitative composition of the compounds and reaction masses, the following analysis methods were used: gas–liquid chromatography (on the Kristall 2000M hardware-software complex), chromatomass spectrometry on an Agilent 6850 instrument equipped with an Agilent 19091S-433E capillary column (30 m × 250 μm × 0.25 μm), and nuclear magnetic resonance spectroscopy (on a Bruker DRX 400 instrument with an operating frequency of 400 MHz).

Results. A significant quantity of meta-tert-butylcumene was obtained by the alkylation of cumene with isobutylene using several catalysts, along with para-tert-butylcumene. This study also showed that the use of the catalysts Amberlyst 36 Dry and KU-2-8 during alkylation in a closed system (autoclave) led to the formation of isobutylene oligomers, often in quantity greater than the target reaction product. Simultaneously, the alkylation of cumene with tert-butyl alcohol in the presence of concentrated sulfuric acid enabled the obtainment of only one isomer, para-tertbutylcumene, which is essential for the further production of high-purity para-tert-butyl phenol.

Conclusions. Sulfuric acid alkylation of cumene with tert-butyl alcohol enabled the obtainment of an individual para-isomer of tert-butylcumene with a yield of 87–89% for the loaded tert-butyl-alcohol with a cumene conversion of ~30%.

Objectives. The purpose of this analytical review is to evaluate the market for osteoplastic materials and surgical implants, as well as study the features of new-generation materials and the results of clinical applications.

Methods. This review summarizes the volumes of research articles presented in the electronic database PubMed and eLIBRARY. A total of 129 scientific articles related to biological systems, calcium phosphate, polymer, and biocomposite matrices as carriers of pharmaceutical substances, primary recombinant protein osteoinductors, antibiotics, and biologically active chemical reagents were analyzed and summarized. The search depth was 10 years.

Results. Demineralized bone matrix constitutes 26% of all types of osteoplastic matrices used globally in surgical osteology, which includes neurosurgery, traumatology and orthopedics, dentistry, and maxillofacial and pediatric surgery. Among the matrices, polymer and biocomposite matrices are outstanding. Special attention is paid to the possibility of immobilizing osteogenic factors and target pharmaceutical substances on the scaffold material to achieve controlled and prolonged release at the site of surgical implantation. Polymeric and biocomposite materials can retard the release of pharmaceutical substances at the implantation site, promoting a decrease in the toxicity and an improvement in the therapeutic effect. The use of composite scaffolds of different compositions in vivo results in high osteogenesis, promotes the initialization of biomineralization, and enables the tuning of the degradation rate of the material.

Conclusions. Osteoplastic materials of various compositions in combination with drugs showed accelerated regeneration and mineralization of bone tissue in vivo, excluding systemic side reactions. Furthermore, although some materials have already been registered as commercial drugs, a plethora of unresolved problems remain. Due to the limited clinical studies of materials for use on humans, there is still an insufficient understanding of the toxicity of materials, time of their resorption, speed of drug delivery, and the possible long-term adverse effects of using implants of different compositions.

Objectives. The determination of the phase relations, crystallographic characteristics, microstructure features, and atomic crystal structure of zirconium oxide crystals that are partially and completely stabilized by yttrium oxide additives, and the identification of the crystallographic and crystal-chemical correlations with the physicochemical properties of single crystals.

Methods. The neutron structure of the crystals was studied using the neutron time-of-flight and constant wavelength methods using a high-resolution Fourier diffractometer on the IBR-2 pulsed fast reactor and a four-circle neutron diffractometer “Syntex.” Single crystals were grown by directed crystallization from the melts of mixtures (1 − х)ZrO₂ ∙хY₂O₃ , х = 0.03 and х = 0.12 with different growth rates (10 and 40 mm/h).

Results. It was observed that when growing single crystals with x = 0.03–0.05, the crystal was stratified into cubic and tetragonal phases, and the ratio between the phases depended on the growth rate. At a growth rate of 40 mm/h, the content of the cubic phase was insignificant. In the crystals of partially stabilized zirconium dioxide (ZrO₂) with the additions of 3 mol % Y₂O₃, the coherent coexistence of cubic and tetragonal phases was established, and the twin law for a tetragonal component (rotation of unit cell axis by 90° around the a (b) axis) that was observed during the phase transition from high-temperature cubic phase to tetragonal phase was determined. For the fully stabilized zirconium oxide of the cubic symmetry (with 12 mol % Y₂O₃), the 0.3 Å displacements of oxygen atoms from their partial structural positions in the directions [100] and [111] were determined. These displacements correlated with the directions of the ion transport.

Conclusions. Previous studies have shown that the ratio between the cubic and tetragonal phases of the single crystals of the ZrO₂ –Y₂O₃ system depends on the growth rate of the single crystals. The content of Y₂O₃ in the cubic and tetragonal phases of a single crystal was determined using the non-destructive neutronography method on the same volume sample of a solid solution of this system. Moreover, the displacements of oxygen atoms from the main position of the crystal were determined.

Objectives. Ferroelectrically hard piezoelectric ceramics are in demand for high-power applications in piezotransformers, ultrasonic emitters, and piezo motors, which requires a combination of high piezoelectric characteristics and mechanical quality factors in it. The aim of this research was to reveal the main regularities in the microstructure and functional characteristic formation of ferroelectrically hard piezoceramics based on two widespread chemical systems, Pb(Zr_xTi_1-x)O₃ and (Na_1-xK_x)NbO₃, through various technological modes of production. In this study, two fundamentally different technological ways of forming a dense microstructure on the example of above systems have been employed to obtain the best set of dielectric, piezoelectric, and mechanical parameters for practical applications. In the case of lead-containing ceramics, various sintering technologies have been used, including conventional ceramic, hot pressing, and spark plasma sintering.

Methods. The microstructure of the piezoelectric ceramics was investigated using electron microscopy, and the functional characteristics were assessed in terms of mechanical and piezoelectric properties. The density values were determined by hydrostatic weighing in octane, the relative dielectric permittivity was measured using an LCR meter, and the values of the piezoelectric coefficient and mechanical quality factor were gathered using the resonance–antiresonance method.

Results. This research has identified that spark plasma sintering technology makes it possible to obtain high-density samples, which contain a homogeneous microstructure and double the figure-of-merit values, for use in high-power piezoelectric devices that operate at piezoresonance frequencies. It also found that the addition of a small amount of CuNb₂O₆ (x = 0.025) to lead-free solid solutions leads to the formation of a liquid phase during sintering, thereby creating a compacted microstructure with relative density values (96%) that have practical limitations in conventional ceramic technology. An increase in both the piezoelectric and mechanical properties, which leads to a twofold increase in the values of the quality indicator, was also observed.

Conclusions. It is possible to increase, and even to double, the functional characteristics of both lead-containing and lead-free ferroelectrically hard piezoceramics by varying the technology used in the manufacturing process. By using spark plasma sintering technology with lead-containing ceramics, it is possible to reduce the optimum sintering temperature by 200 °C and the sintering time by more than 20 times, thus reducing production costs.

Objectives. In this biosimilar research, we compare the monoclonal antibody eculizumab obtained from different drugs [original Soliris^® (Alexion Pharmaceuticals) and candidate Elizaria^® (Generium)] by intact mass measurement and middle-up mass spectrometry analysis to enhance the role of mass spectrometry methods in biopharmaceutical development processes.

Methods. The intact mass measurement is performed using a high-resolution ESI-MS. The middle-up analysis is performed by reversed-phase high-performance liquid chromatography with ESI-MS detection, subsequent IdeS treatment of antibodies, and disulfide bond reduction.

Results. We have shown some small differences between the original and candidate drugs in the minor glycans level. Man5 glycan is only found in the original Soliris, and G0 is only found in the Elizaria. Glycation sites are also found in the light chain and Fd subunits of the original Soliris. The glycation level does not exceed 4.4%. The non-clipped C-end lysine level and G0F glycan levels are slightly lower in the original Soliris. All registered differences are not crucial for eculizumab’s quality and do not affect its effectiveness and preclinical safety. Generally, the results show a high level of similarity between the original and candidate drugs.

Conclusions. The comparative mass spectrometry analysis of eculizumab in the original Soliris and Elizaria allows us to estimate their high degree of similarity by molecular masses and major modification profiles.

Objectives. Determination of target products and byproducts is necessary for the quality control of phthalonitrile monomer synthesis as well as production scaling and performing related kinetic studies. High-performance liquid chromatography (HPLC) is a simple and affordable method for quantitative chemical analysis, which also verifies the quality of raw materials. The objective of this study was to develop an HPLC technique for determining the composition of the reaction mixture in the synthesis of 1,3-bis(3,4-dicyanophenoxy)benzene (DPB).

Methods. Reversed-phase HPLC was used to quantitatively analyze the reaction mixture.

Results. A simple and rapid method for the quantitative HPLC analysis of phthalonitrile monomers and their mixtures with reagents was developed. Reaction times and the accumulation of byproducts were also studied.

Conclusions. The successful performance of the developed technique allows us to recommend it for practical applications. The results obtained for reactors of different sizes have good convergence, and DPB synthesis was successfully scaled up to intermediate scale equipment.