Russian Journal of Applied Chemistry最新文献

This review article explores the potential of lignin as a sustainable alternative to conventional petroleum-based adhesives. Conventional adhesives derived from petroleum sources have been widely used in industrial, medical, and household applications. However, the depletion of petroleum resources and environmental and human health concerns have prompted the search for bio-based and environmentally friendly alternatives. Lignin, a biodegradable substance abundant in nature, has emerged as a promising substitute due to its non-toxic nature, three-dimensional structure, and functional groups. Replacing the chemicals used in conventional adhesives with lignin can reduce production costs, and the resulting adhesives exhibit decreased toxicity. Furthermore, lignin can be combined with biobased materials to create bio-based adhesives. This article provides an overview of lignin extraction methods, explores the diverse applications of lignin in various industries, discusses chemical modifications of lignin, and specifically focuses on the production of lignin-based adhesives. Finally, the challenges associated with lignin-based adhesive production are addressed.

This study reports the hydrothermal synthesis of hierarchical aluminum phosphate molecular sieves doped with V, Cu, Fe, and Ni. The catalysts were characterized by XRD, SEM, EDS, XPS, NH₃-TPD, and N₂ adsorption-desorption from the perspectives of structure, morphology, acidity pore size, etc., which confirmed that the metals successfully infiltrated the molecular sieve skeleton. The synthesized D-MeAPO-5 molecular sieve was applied to the oxidation of benzene to the preparation of phenol. It was found that the catalytic effect of the D-VAPO-5 molecular sieve was superior to other catalysts. The conversion rate of benzene and selectivity of phenol were 27.0% and 80.4%, respectively, indicating that the activation ability of the C-H bond on the V-benzene ring was stronger. For optimal experimental design, the response surface method was carried out using D-VAPO-5 as the catalyst and phenol yield as the response value. In addition, a quadratic model was established for four influencing factors and phenol yield, and the significance of the factors was found to be as follows: reaction temperature>H₂O₂ dosage>catalyst dosage>reaction time.

The goal of this investigation effort was to organize activated carbon from olive stone through by 0.01 M D₂EHPA. The adsorption ability of carbon with cadmium and zinc existed also studied. Focuses of metals were examined through using flame atomic absorption spectrophotometry. The factors that disturb the adsorption, such as contact time, acid concentration, solid liquid ratio, RPM, and temperature, have been considered and enhanced conditions were determined. The results showed that the maximum adsorption capacities of carbon were found to Cd²⁺ and Zn²⁺with 28.0 and 22.17 mg/g, respectively. The Langmuir adsorption model might be used to clarify the adsorption isotherm with the pseudo-second order and The Cd²⁺ and Zn²⁺sorption process onto the olive stone (OS) occurred spontaneously (­–ΔG), in an exothermic nature (–ΔH), and with increased non randomness (–ΔS).

In this paper, magnesium acrylate (AMgA) was used as the polymerization monomer, glycerol (GL) was used as the modifier, ammonium persulfate (APS) and triethanolamine (TEA) were selected as the redox initiation system to prepare polymagnesium acrylate/glycerol (PAMgA/GL) supramolecular conductive hydrogels by free radical polymerization. The antifreezing property, water retention, tensile properties, adhesion, self-healing property, conductivity and strain sensing properties of the hydrogels were analyzed. The results revealed that: when the GL content was 30 wt %, the PAMgA/GL hydrogels exhibited excellent toughness, the tensile strength was 0.152 MPa, and the elongation at break can reach 534%, the conductivity was 0.277 S m^–1, and the four times adhesion strength to 0.0407 MPa. When the tensile strain reached 500%, the gauge factor (GF) was 2.45, exhibiting great strain sensing properties. In addition, the PAMgA/GL hydrogels demonstrated good antifreezing property, water-retention and self-healing properties. The results of this study provide theoretical guidance for the design and preparation of new materials for human body detection.

Sorption of carbon dioxide, methane, and hydrogen in additive poly(5-norbornyl-2-norbornene) was studied at pressures in the interval 0–10 bar and temperatures in the interval 10–60°C. The isotherms obtained were described by the double sorption model including both Langmuir and Henry sorption models. The double sorption model parameters and the gas solFigubility coefficients in the polymer at different pressures and at infinite dilutions were determined. The solubility selectivity values were calculated from the data obtained. The highest solubility selectivity for the CO₂/CH₄ gas pair is reached at 20°С. Owing to high values of this selectivity, additive poly(5-norbornyl-2-norbornene) can be considered as a candidate membrane material for the separation of gas mixtures containing CO₂.

A procedure was developed for preparing 2-alkylthio-5-(1,2,4-triazol-1-ylmethyl)-1,3,4-oxadiazoles by alkylation of 5-(1Н-1,2,4-triazol-1-ylmethyl)-1,3,4-oxadiazole-2-thione with β-bromophenetoles in the presence of triethylamine in acetone with up to 90% yield. The in vitro tests of the target compounds for fungicidal activity toward six species of phytopathogenic fungi of different taxonomic classes show that the S-halophenoxyethyl-substituted derivatives surpass a reference fungicide, Triadimefon, in the activity toward Venturia inaequalis, Rhizoctonia solani, and Bipolaris sorokiniana.

The hydrogen decrepitation of end-of-life NdFeB magnetic alloys was studied. End-of-life magnets extracted from PC hard drives were taken as a material for the experiments. The choice of these items is governed by their low cost, easy removal from PC, and small size. The magnets were demagnetized at 623 K in a medium vacuum for 4 h, which was followed by three-step cleaning of their surface to remove the electroplated coating, oxidized surface layer, and adsorbed impurities and moisture. The first step of the cleaning was sandblasting with slag shot fed at a pressure of 300 kPa. The second step was chemical etching with solutions of dilute acids (1–3% HCl, HNO₃, or H₂SO₄ in distilled water), followed by washing in acetone. The third step was heat treatment in a vacuum, consisting in rapid heating in a shaft furnace of magnet samples placed after etching in an autoclave, with several exposures in the temperature interval 373–573 K in a medium vacuum. After these operations, the samples were quenched by placing the hot autoclave into a vessel with ice-cold water, preceded by filling the autoclave with argon. Then, alloys of the NdFeB system without removing from the autoclave were subjected to hydrogen decrepitation performed in the temperature interval from 298 to 473 K at an excess hydrogen pressure of 30 to 210 kPa to determine how these parameters influence the properties of the hydride powders obtained and the amount of hydrogen taken up. The hydrogen for the decrepitation was generated by direct desorption from the heated hydride of the LaNi₅ alloy. In the pressure range 30–70 kPa and room temperature, alloys of the NdFeB system transform into hydrides. The chemical reaction with hydrogen starts instantaneously without a period of primary hydrogen adsorption. The hydride powders obtained, containing no less than 0.459 wt % hydrogen, are very brittle and can be finely milled (100-g portion) in a planetary ball mill within 6 min to obtain a powder with the particle size smaller than 20 μm. The analysis of the surface of the finely milled hydride powder particles revealed no oxygen (≤1 wt %).

The physicochemical features of the solubilization of gossypol (GS) with polyivinylpyrrolidone (PVP) were studied. In contrast to the initial polyphenol, the solubilization product is a water-soluble supramolecular complex. As shown by IR spectroscopy, the complexation of PVP with GS occurs via hydrogen bonding between the carbonyl oxygen atom of the pyrrolidone ring of the polymer and hydroxyl proton of polyphenol. The relative viscosity of aqueous solutions of the supramolecular complex depends on its composition and passes through a minimum with the lowest value of the PVP : GS ratio close to 2 : 1. That is, at this component ratio, the structure of the complex in an aqueous medium is the most compact. The GS solubilization with PVP can be presented as adsorption of the polyphenol onto the polymer and can be described by the Langmuir monomolecular adsorption theory.

Addition polymerization of 3-methyl-3-phenylcyclopropene and 3,3-di(n-propyl)cyclopropene in the presence of a palladium complex containing an acyclic diaminocarbene ligand was studied. When activated with the organoborate (Na⁺[B(3,5-(CF₃)₂C₆H₃)₄]^–), such complex catalyzes the addition polymerization of substituted cyclopropenes. The polymerization occurs selectively without opening of the cyclopropane ring. The copolymerization of 3,3-di(n-propyl)cyclopropene with a monomer of the norbornene series (5-ethylidene-2-norbornene) was monitored by a decrease in the intensity of the characteristic signals in the ¹H NMR spectra of the corresponding monomers. The substituted cyclopropenes were found to be more active monomers than norbornenes in the addition polymerization. The addition homopolymers of 3-methyl-3-phenylcyclopropene and 3,3-di(n-propyl)cyclopropene were characterized by differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction.

The effect that introduction of cerium oxide into oxide systems based on chromium and silicon exerts on the catalytic properties of these systems in nonoxidative propane dehydrogenation in a flow-through system with a fixed catalyst bed was studied. The characteristics of the catalysts CrO_x–SiO₂ and CrO_x–CeO₂–SiO₂, both containing 9 wt % CrO_x assuming the Cr₂O₃ stoichiometry, were compared. The СеО₂ content of the ternary system was 52 wt %. The catalysts were characterized by X-ray diffraction analysis, scanning electron microscopy, Raman spectroscopy, electron paramagnetic resonance, X-ray photoelectron spectroscopy, temperature-programmed reduction with hydrogen, and thermal analysis. In the initial period of the reaction, the catalyst containing CeO₂ demonstrated higher propane conversion at 500 and 550°С and higher deactivation rate compared to CrO_x–SiO₂. Both catalysts can be regenerated by treatment in an air stream at 550°С for 30 min. Cerium dioxide favors the reduction of chromium in high oxidation states to form active reaction sites, Cr³⁺ ions, ensures higher dispersity of the chromium oxides, and favors partial oxidation of coke deposits in the initial period of the catalyst operation.