Eurasian Journal of Chemistry最新文献

{"title":"Synthesis of Water-Soluble Polyethylene Glycol Fumarates for Biomedical Applications","authors":"Y. Tazhbayev, A. Kazhmuratova, L. Zhaparova, Ulugbek B. Tuleuov, Yermauyt Nassikhatuly, Elizaveta S. Mitricheva, Alexander L. Kwiatkowski, Andrey V. Shibaev","doi":"10.31489/2959-0663/2-24-7","DOIUrl":"https://doi.org/10.31489/2959-0663/2-24-7","url":null,"abstract":"Polyethylene glycol fumarate (PEGF) with controlled structural composition has been obtained for further synthesis of double network crosslinked hydrogels for biomedical applications. The copolymer has been synthesized by polycondensation reaction of fumaric acid and polyethylene glycol (PEG-600). Molecular weight of PEGF has been determined by gel permeation chromatography to be approximately 6000 Da with gel permeation chromatography. The polycondensation of fumaric acid and PEG-600 was studied throughout the reaction process. The structure of the reaction product has been evidenced using FTIR- and 1H NMR-spectroscopy. The quantitative ratios of the amount of –C=C– bonds and –COO groups to –C=O groups in the obtained PEGF have been estimated from IR-spectra for different synthesis time. The time-dependence of molar ratio of double bonds to methyl groups in PEGF has been obtained from corresponding 1H NMR-spectra. FTIR and 1H NMR-spectroscopy, both, demonstrate that after the end of reaction the unsaturated –C=C– double bonds remain in the structure of the macromonomer, that is essential for further preparation of cross-linked hydrogels. The addition of the tightly cross-linked network of polyvinyl alcohol leads to formation of highly tough biocompatible material for preparation of the artificial meniscus which can further be used as a solution n the treatment of diseases such as osteoarthritis.","PeriodicalId":514223,"journal":{"name":"Eurasian Journal of Chemistry","volume":"49 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141358733","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}

{"title":"Fabrication of Hydrophobic PET Track-Etched Membranes using 2,2,3,3,4,4,4-Heptafluorobutyl Methacrylate for Water Desalination by Membrane Distillation","authors":"A. K. Shakayeva, A. B. Yeszhanov, A. Zhumazhanova, I. Korolkov, M. V. Zdorovets","doi":"10.31489/2959-0663/2-24-5","DOIUrl":"https://doi.org/10.31489/2959-0663/2-24-5","url":null,"abstract":"The world is currently facing a drinking water problem. Human activity, climate change and pollution of existing water bodies are exacerbating the problem. The scientists around the world are currently trying to purify water using effective and inexpensive methods. One such method is membrane distillation. Membrane distillation is a versatile thermally driven membrane separation process. This method of water purification has the potential to remove salts and other non-volatile components. The work is concerned with the desalination of salt solutions by membrane distillation using ion-track membranes based on polyethylene terephthalate (PET). PET ion-track membranes (PET TMs) were modified by photoinitiated graft polymerization of 2,2,3,3,4,4,4-heptafluorobutyl methacrylate (HFBMA) to make them hydrophobic. Optimal polymerization conditions (monomer concentration, reaction time) were determined, which led to an increase of water CA from 51 to 105°. The obtained membranes were used to purify the solution from NaCl. The effect of salt concentration as well as membrane properties on performance and degree of purification was studied. The results show that large pore size PET TMs modified with HFBMA has the potential to desalinate water in an efficient manner.","PeriodicalId":514223,"journal":{"name":"Eurasian Journal of Chemistry","volume":"124 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141126270","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}

{"title":"Effect of Heat Treatment on the Supramolecular Structure of Copolymers Based on Poly(propylene glycol fumarate phthalate) with Acrylic Acid","authors":"A. Sarsenbekova, Abylaikhan N. Bolatbay, David Havlicek, Zhannur A. Issina, Assiya Zh. Sarsenbek, Nurgul A. Kabdenova, Muslim A. Kilybay","doi":"10.31489/2959-0663/2-24-9","DOIUrl":"https://doi.org/10.31489/2959-0663/2-24-9","url":null,"abstract":"Previous studies investigating the thermal decomposition of p-PGFPh:AA copolymers in an inert atmosphere have provided only a general understanding of the changes that occur during thermolysis. Comprehensive studies are required to gain a better understanding of these processes [1]. The most comprehensive information on the influence of various factors on both the kinetics and the supramolecular structure of the resulting products can be obtained by combining the method of thermal analysis with IR, mass spectrometry, and scanning electron microscopy. The compounds studied have two different compositions, namely p‑PGFPh:AA 6.77:93.23 mol % and p-PGFPh:AA 86.67:13.33 mol %. These compounds were then subjected to a thermolysis process, which resulted in the emission of gases and a decrease in sample weight. The degradation process can be divided into three stages: 1) Depolymerization of the main chain; 2) Depolymerization of the side chain; 3) Final decomposition. These processes occur sequentially at different temperature ranges. According to TG- and DTG studies, complete decomposition of p-PGFPh:AA copolymers occurred at Tterm = 340–350 °C. In this temperature range, a slight loss of sample mass (less than 10 wt %) was observed along with a slight gas evolution. The main gaseous products from the transformation of the studied samples were CO and CO2. This was supported by IR-CO (2000–2200 cm−1) and CO2 (2310–2370 cm−1) as well as mass spectrometric observations. The final products resulting from the thermolysis of p-PGFPh:AA copolymers were examined under an electron microscope. The results showed a similar morphological pattern of mesostructures with sizes ranging from 0.3–1.5 μm, which were observed depending on the porous structure of the initial polymer material. Based on the experimental data, it can be concluded that the p-PGFPh:AA copolymers (in proportions of 6.77:93.23 mol % and 86.67:13.33 mol %) have a relatively high degree of resistance to heating and do not undergo any changes in chemical composition, particle size and shape. In conclusion, the results clearly indicate that the selection of conditions for pyrolysis plays a crucial role in increasing the thermal stability of polymeric materials. This method allows for purposeful changes in the structure and properties of polymers.","PeriodicalId":514223,"journal":{"name":"Eurasian Journal of Chemistry","volume":"5 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140962402","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}

{"title":"New Method for Obtaining Carboxylic Derivatives of Oxazolo[5,4-b]pyridine Based on 3-Aminopyridine-2(1H)-ones","authors":"I. Palamarchuk, I. Kulakov","doi":"10.31489/2959-0663/2-24-11","DOIUrl":"https://doi.org/10.31489/2959-0663/2-24-11","url":null,"abstract":"Current methods for synthesis of oxazolo[5,4-b]- and oxazolo[4,5-b]pyridines have several limitations, such as severe reaction conditions, lengthy reaction times, low yields and concurrent formation of side reaction products. This article presents the results of study focused on a one-step method for the synthesis of new derivatives of oxazolo[5,4-b]pyridine incorporating an aliphatic carboxylic group as a linker. During the investigation of acylation reactions of 3-aminopyridine-2(1H)-ones with cyclic anhydrides of dicarboxylic acids (succinic, maleic and glutaric), it was found that the monoamides formed at the initial stage undergo intramolecular cyclization yielding derivatives of oxazolo[5,4-b]pyridine. Subsequently, the reaction conditions were studied and optimized to achieve the target compounds with high yield and purity. The potential anti-inflammatory activity of the obtained derivatives of oxazolo[5,4-b]pyridine was evaluated by molecular docking method using AutoDock Vina software. Compounds 11-14b exhibited higher binding affinity with the selected target protein Prostaglandin synthase-2 (1CX2) compared to the reference anti-inflammatory drug diclofenac. Thus, taking into account the results of in silico analyses, the newly synthesized oxazolo[5,4-b]pyridine derivatives based on 3-aminopyridine-2(1H)-ones are promising candidates for further investigation of their potential anti-inflammatory activity through in vivo methods.","PeriodicalId":514223,"journal":{"name":"Eurasian Journal of Chemistry","volume":" 47","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140990696","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}

{"title":"Characterization Electrospun Nanofibers Based on Cellulose Triacetate Synthesized from Licorice Root Cellulose","authors":"Siroj Sh. Shakhabutdinov, S. M. Yugay, N. Ashurov, Doniyor J. Ergashev, A. Atakhanov, S. Rashidova","doi":"10.31489/2959-0663/2-24-2","DOIUrl":"https://doi.org/10.31489/2959-0663/2-24-2","url":null,"abstract":"Cellulose triacetate (CTA) nanofibers were formed by electrospinning using two binary solvent systems: methylene chloride/ethanol and chloroform/acetone. Previously, licorice root cellulose (LRC) with a degree of polymerization (DP) of 710 was extracted from licorice root waste by alkaline treatment and hydrogen peroxide bleaching at high temperatures. Then CTA with a degree of substitution (DS) of 2.9 and an average molecular weight of 175 kDa was synthesized from LRC using acetic acid and acetic anhydride, sulfuric acid was as a catalyst. The influence of the electrospinning process and various solvent systems on the morphology and structure of nanofibers is studied. The structure and morphology of the nanofibers were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and the sorption characteristics were also investigated. The results showed that the morphology and structure of nanofibers depended on the solvent mixture used. The average diameters of the CTA nanofibers with grooved morphology varied 200-700 nm (solvent methylene chloride/ethanol) and the dumbbell-shaped (flat ribbon) CTA nanofibers in a wide range from 200 nm to 4 mkm (solvent chloroform/acetone).","PeriodicalId":514223,"journal":{"name":"Eurasian Journal of Chemistry","volume":"68 s276","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002300","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}

{"title":"Natural Polyelectrolyte Hydrogels with Two Types of Cross-Links with Different Energy","authors":"D. Muravlev, A. P. Doroganov, O. Philippova, Andrey V. Shibaev","doi":"10.31489/2959-0663/2-24-12","DOIUrl":"https://doi.org/10.31489/2959-0663/2-24-12","url":null,"abstract":"For the first time, gels of a polymer cross-linked by two types of ionic cross-links of different energies, namely trivalent chromium (III) ions and divalent iron (II) ions, were prepared. The negatively charged polysaccharide xanthan, a polyelectrolyte of natural origin, was used as a polymer. A study of xanthan gels cross-linked with each cross-linker separately was carried out to identify the optimal concentrations of each cross-linker for the production of a double cross-linked gel. The mechanical properties of hydrogels under oscillatory shear deformations were then studied. It was demonstrated that the simultaneous use of two cross-linkers resulted in a synergistic increase in the elastic modulus (plateau storage modulus) compared to gels cross-linked with each cross-linker separately. For a gel with two types of cross-links, the elastic modulus was 16 Pa. In contrast, for gels cross-linked with either chromium (III) cations or iron (II) cations, the elastic modulus was approximately 0.6 and 0.5 Pa, respectively. The strong effect can be attributed to the different nature of cross-linking between xanthan macromolecules and chromium (III) and iron (II) cations, as well as the different strength of the cross-links formed. The optimal range of pH values was determined in which a synergistic increase in the elastic modulus of gels with two types of cross-links was observed compared to the corresponding gels cross-linked with each cross-linker separately. Consequently, the concurrent utilisation of two cross-linking agents that generate cross-links with disparate energy levels represents an efficacious strategy to improve the tensile strength of polymer hydrogels.","PeriodicalId":514223,"journal":{"name":"Eurasian Journal of Chemistry","volume":"27 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141005334","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}

{"title":"Effect of Salt Content on Solubilization of Hydrophobic Polymer by Wormlike Micelles of Ionic Surfactant","authors":"A. Kwiatkowski, Pavel V. Kalinin, O. Philippova","doi":"10.31489/2959-0663/2-24-15","DOIUrl":"https://doi.org/10.31489/2959-0663/2-24-15","url":null,"abstract":"The effect of concentration of inorganic salt KCl on solubilization of hydrophobic polymer poly(4-vinylpyridine) (P4VP) in aqueous solutions of ionic surfactant potassium oleate was experimentally investigated. As was shown by rheology, in the range of concentrations from 1 to 5 wt.% of salt the polymer-free solutions of surfactant mainly contain linear wormlike micelles (WLMs). The formation of branched WLMs was observed in the solutions containing 5-9 wt.% of KCl. In the presence of higher salt content the phase separation occurred, indicating the formation of a highly branched saturated network of WLMs. Enhanced screening of the charged groups of potassium oleate by oppositely charged ions of KCl caused elongation and branching of micelles that reflected in zero-shear viscosity of the solutions passing through the maximum. In the phase diagram, the saturation concentration with P4VP of both linear and branched WLMs decreased with increasing salt content. In the case of linear WLMs, this could be explained by the constant number of embedded polymer chains per 1 WLM, while simultaneously decreasing number of WLMs in the system. As for the branched WLMs, it was caused by shortening of the linear parts of micelles due to the formation of branching points. For this reason, almost no P4VP was dissolved in the solution containing the highly branched saturated network.","PeriodicalId":514223,"journal":{"name":"Eurasian Journal of Chemistry","volume":"29 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140659694","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}

{"title":"Detecting Shape of Hybrid Polymer/Surfactant Micelles: Cryo-Transmisson Electron Microscopy, Small-Angle Neutron Scattering and Dynamic Light Scattering Studyic light scattering study","authors":"A. Kwiatkowski, V. Molchanov, Anton S. Orekhov, Alexander I. Kuklin, O. Philippova","doi":"10.31489/2959-0663/2-24-13","DOIUrl":"https://doi.org/10.31489/2959-0663/2-24-13","url":null,"abstract":"In-depth study of shape of hybrid micelles in the micellar solutions of anionic surfactant potassium oleate, containing hydrophobic polymer poly(4-vinylpyridine) (P4VP) was conducted via cryo-transmission electron microscopy (cryo-TEM), small-angle neutron scattering (SANS) and dynamic-light scattering of visible light (DLS). Direct visualization of the solutions with cryo-TEM evidenced the coexistence of polymer-free spherical micelles and branched rodlike hybrid micelles with mean length of 200 nm and radius of 2 nm, governed by contour length of solubilized P4VP and length of hydrophobic “tail” of potassium oleate, respectively. The formation of branches in the hybrid micelles was explained by attaching the thermodynamically unfavorable end-caps of micelles to their polymer-loaded cylindrical fragments. By SANS it was shown that the cylindrical local shape and the radius of the micelles are independent of the concentration of embedded P4VP. Relaxation processes in the solutions were investigated with DLS. Three relaxation modes were observed for hybrid micelles, similar to polymer-free wormlike micelles. Fast and medium relaxation modes were attributed to diffusion of entangled micellar chains and their segments, respectively. The slow mode was related to electrostatic repulsion between similarly charged hybrid micelles.","PeriodicalId":514223,"journal":{"name":"Eurasian Journal of Chemistry","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140662779","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}

{"title":"Multicomponent Synthesis of Novel Unsymmetric 6-Aryl Substituted 5-Nitropyridines","authors":"Ilya Kulakov, S. Chikunov, Andrey Elyshev, I. Kulakov","doi":"10.31489/2959-0663/2-24-3","DOIUrl":"https://doi.org/10.31489/2959-0663/2-24-3","url":null,"abstract":"We have previously studied a multicomponent reaction for the synthesis of unsymmetrical 5-nitro-1,4-dihydropyridines using unsubstituted 2-nitroacetophenone, 1,3-dicarbonyl compounds, and various aldehydes such as formaldehyde, acetaldehyde, and furfural. This paper reports the use of unsymmetrical 3-acetyl-5-nitro-1,4-dihydropyridines containing aryl substituents at the 6-position in a multicomponent synthesis reaction. The starting aryl-substituted nitroacetophenones were prepared by two methods. The first method involved the two-step Katritzky method, which is described in the literature. This method consists of preparing N-acylbenzotriazoles from the corresponding substituted derivatives of benzoic acid and 1,2,3-benzotriazole in the presence of thionyl chloride. This is followed by C-acylation of nitromethane in supernatron medium (t-BuOK – DMSO). A number of 2-nitroacetophenone derivatives were prepared from more commercially available aromatic aldehydes by the Henry reaction with nitromethane followed by oxidation of the resulting secondary nitroalcohols. The multicomponent reaction of 6-aryl-substituted 5-nitro-1,4-dihydropyridines and their subsequent aromatization into 5-nitropyridines allowed us to reduce the overall reaction time by more than 40 times and to increase the total yield of 5-nitro-6-arylpyridines by an average of twofold compared to the method described in the literature. Furthermore, the 3-acetyl-5-nitropyridines we have obtained are significant intermediates in the synthesis of novel, more complex heterocyclic systems with potential biological activity. These systems include δ-carbolines and epoxybenzooxocyno[4,3-b]pyridines, which are currently of great interest for the study of their properties.","PeriodicalId":514223,"journal":{"name":"Eurasian Journal of Chemistry","volume":"10 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140666273","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}

{"title":"Catalytic Dehydration of Biomass-Derived Feedstocks to Obtain 5-Hydroxymethylfurfural and Furfural","authors":"Harry Megbenu, Zhanat Azhikhanova, Gulnaz Ingkar, Nurzhan Rakhimgaliyev, Aizada Mels, Almaz Kenzheshov, Almas Askarov, Minavar Shaimardan, N. Nuraje","doi":"10.31489/2959-0663/2-24-1","DOIUrl":"https://doi.org/10.31489/2959-0663/2-24-1","url":null,"abstract":"Biomass-produced furanics, furfural and 5-hydroxymethylfurfural (5-HMF), are considered as vital platform chemicals used in the production of active pharmaceutical ingredients (APIs), commodity goods, and fuels. The primary challenge associated with their production pertains to the high cost involved in scaling up to industrial levels. Consequently, it is essential to explore more cost-effective options that yield efficient end products. In this study, the use of Lewis and Brønsted acids such as HCl and AlCl3 enhances the isomerization of glucose through catalytic dehydration into 5-HMF. It was observed that employing moderate reaction conditions increased the yield of 5-HMF to 44.94 % and 50.60 % respectively, with changes in HCl concentration and AlCl3 mass loading. The suitable conditions to achieve the highest yield of 5-HMF were 100 μL of HCl, 0.75 g of AlCl3, reaction temperature 150 °C, and reaction time 4 h. In the second experiment, corncob was converted into furfural in the presence of 20 % H2SO4, in combination with NaCl as a promoter. The optimal conditions under which a yield of 44.77 % was achieved were as follows: 50 mL of 20 % H2SO4, reaction temperature 140 °C, 0.5 g of NaCl, 5 g of corncob, and reaction time 160 min. Furthermore, a proposed reaction mechanism was outlined to elucidate the pathway for the production of the aforementioned platform chemicals.","PeriodicalId":514223,"journal":{"name":"Eurasian Journal of Chemistry","volume":"49 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140667978","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}