A series of 1,3-disubstituted ureas was synthesized in 85–93

The features of forming film materials based on acid-soluble chitosan are investigated. The dependence of the physicomechanical and sorption properties of the film materials on the amount of the introduced cross-linking agent (glutaraldehyde) and plasticizer (polyoxyethylene glycol) was found. The use of glutaraldehyde is proposed to control the sorption of aqueous media by chitosan-based film materials due to the formation of cross-links that afford the films with water absorption of 200–650

Copper-based metal-organic frameworks (Cu-MOFs) were successfully used for the amination of aryl iodides for the first time. The conditions were selected using four different Cu-MOFs in a model reaction of n-octylamine with iodobenzene. Efficient reaction requires the use of O,O′-bidentate ligands (2-acetylcyclohexanone, 2-isobutyrylcyclo-hexanone, rac-1,1′-bi(2-naphthol), or rac-BINOL), and, in the best cases, the yields of N-octylaniline can exceed 80

The efficiencies of copper-containing metal–organic coordination polymers (Cu-MOFs) and com­mercially available unsupported copper nanoparticles (CuNPs) in the amination of 2-iodopyridine, 2-bromo­pyridine, 2-bromo-5-(trifluoromethyl)pyridine, and 2-bromo-6-(trifluoromethyl)pyridine with n-octylamine and adamantane-containing amines with different steric environments of the amino group have been compared. Under the optimized conditions, the yields of the amination products in the presence of both catalytic systems were generally similar. In the reactions with 2-bromopyridine, increased reactant concentration and the use of 2 equiv of the substrate were necessary to achieve good yields. The presence of a trifluoromethyl group at the 6-position of the pyridine ring improved the yield of the amination products. An increase in steric hindrances at the amino group resulted in an appreciable decrease in the yield under catalysis by Cu-MOFs; however, reactions with such amines were successfully performed in the presence of CuNPs, and CuNPs of the average size 25 nm proved to be superior to bifractional nanoparticles with average sizes of 10 and 80 nm. On the other hand, increased concentration of the reactants in the Cu-MOF-catalyzed amination provided good yields of the target compounds in the absence of a ligand.

In the 1H NMR spectra (DMSO-d6) of 1,3-disubstituted ureas containing the 4,7,7-trimethyl-3-oxo-4-oxabicyclo[2.2.1]heptan-1-yl substituent, the signals for the CH2—CH2 moiety appear as an ADMP-type spin system consisting of four doublets of doublets of doublets with chemical shifts in the range from 1.54 to 2.80 ppm. The experiment in CD3OD showed the disappearance of the signal at δ 2.80 and a change in the multiplicity of the other signals, which is indicative of the selective deuterium exchange of one of the four protons of the CH2—CH2 group for a deuterium atom. This allows the selective modification of compounds containing the oxacamphanyl moiety.

It has been shown that adamantane-containing diamines are highly reactive under conditions of single-stage high-temperature cyclization in a sulfolane–toluene mixture of solvents. Polyimides with the reduced viscosity of 1.3‒1.4 dL/g have been synthesized on their bases, the films of which have exhibited good thermal properties and low yellowness index (1.1‒1.2).

To reduce the flammability of polymers, functional flame retardants have become widespread, among which phosphorus-containing methacrylates occupy a special place. Despite the well-developed issues of their synthesis and use, the search for new monomers of this class remains a demanding task due to their efficiency, environmental friendliness, and a number of other reasons. This review systematizes the results of recent research concerning phosphorus-containing polymerizable monomers of the methacrylate series, the use of which makes it possible to reduce the flammability of the resulting materials and composites.

An overview of the main scientific achievements of Russian universities in the field of organic chemistry over the period 2018–2023 is presented.

The process of hydrolysis of amide groups of polyacrylamide in the presence of a dispersion of nanosized copper particles obtained via the reduction of copper cations with sodium tetraborate has been studied. Quantum-chemical simulations have shown an increase in the effective positive charge on the carbon atom in the amide group upon formation of the complex with copper. Energy of interaction of units of polyacrylamide and polyacrylic acid macromolecules with a unit area of copper nanoparticles has been calculated. The significant difference in the energies leads to replacement of the hydrolyzed amide groups of the polymer from the surface of copper particles by the unreacted amide groups. The degree of hydrolysis of polyacrylamide in the presence of copper particles has been 89%, being 22% in the absence of the particles.

This work is devoted to studying the stability of polymer coatings formed from reactive copolymers of glycidyl methacrylate and fluoroalkyl methacrylates and applied onto textured aluminum and cotton textile surfaces. The stability is determined with respect to the action of aggressive media and mechanical stress. The resulting coatings provide the achievement of long-term stable heterogeneous wetting with initial contact angles as large as 170°, thus preventing the penetration of corrosive agents into the hierarchical structure. The study has shown the influence of the composition of the reactive copolymers containing 3–7 fluorine atoms in a monomer unit on the stability of the polymer coatings with respect to the prolonged exposure to media with different acidities, as well as to cavitation, and abrasive wear.

Methods have been developed for the synthesis of N-[2-(adamantan-2-yl)ethyl]-N′-R-ureas and -thioureas in 36–87

Objectives. To investigate the protective efficacy of unreduced and reduced forms of the condensation product of D,L-camphor and p-ethoxyaniline in nitrile butadiene rubber formulations when compared with the conventional stabilizer N-isopropyl-N′-phenylp-phenylenediamine aged under laboratory and in situ climatic conditions in the tropics.Methods. The thermostabilizing effect of the condensation product of D,L-camphor and p-ethoxyaniline was evaluated by means of infrared spectroscopy using the dynamics of changes in the absorption bands of carbonyl and hydroxyl groups. The features of rubber vulcanization were studied by means of rotorless rheometry. Changes in the physical and mechanical properties of rubbers and degree of cross-linking were evaluated after thermo-oxidative aging in laboratory conditions. They also took into account the results of longterm exposure of samples in undeformed and deformed state in a tropical climate, taking into account meteorological data of the Can Gio climatic testing station.Results. It was found for the first time that condensation products of D,L-camphor and p-ethoxyaniline exhibit a stabilizing effect in formulations of rubbers based on polar nitrile butadiene rubber.Conclusions. According to the results of laboratory and in situ tests, the study established that the use of N-[(1RS,2RS)-camphan-2-yl]4-ethoxyaniline (reduced form) as an antifatigue agent is preferable. This is due to the presence of a mobile hydrogen atom at the nitrogen atom. The protective effect is manifested in terms of the better preservation of elastic-strength properties of rubbers with less change in hardness.

Methods for the preparation of 1-[2-(adamantan-2-yl)ethyl]-3-R-ureas and thioureas by the reaction of 2-(adamantan-2-yl)ethylamine with aromatic isocyanates and isothiocyanates with 36–87% yields were developed. It was found that the displacement of the ethylene bridge from the 1st to the 2nd position of the adamantyl radical does not significantly affect the value of log P and melting points of the corresponding compounds.

В работе исследуется устойчивость полимерных покрытий на основе реакционноспособных сополимеров глицидилметакрилата и фторалкилметакрилатов на поверхности текстурированного алюминия и хлопчатобумажной ткани к действию агрессивных сред и механическому воздействию. Получаемые покрытия обеспечивают достижение стабильного во времени гетерогенного смачивания с начальными углами смачивания до 170°, препятствующего проникновению коррозионных сред внутрь иерархической структуры. Показано влияние состава реакционноспособных сополимеров с содержанием атомов фтора в мономерном звене от 3 до 7 на устойчивость полимерных покрытий к длительным контактам со средами различной кислотности, кавитационному воздействию и абразивному истиранию.

Polyimides play an important role among heat-resistant polymers thanks to their combination of high thermal, electrical, and physico-mechanical properties. Recently, there has been a growing demand for transparent polymer dielectrics used in micro-optoelectronic applications. To produce such polyimides while maintaining their other performance characteristics, several factors must be considered. This article discusses the key ingredients for creating transparent polyimides with enhanced dielectric properties and their modern applications.

A method comprising the use of a fluorinating agent, the Ishikawa’s reagent, at one of its steps was developed for the synthesis of 1,3,5-trifluoroadamantane-7-isocyanate from 3,5,7-trifluoroadamantane-1-carboxylic acid and diphenylphosphoryl azide. The reaction of 1,3,5-trifluoroadamantane-7-isocyanate with fluoroanilines gave 1,3-disubstituted ureas in the yields of 58–73

A procedure has been developed for the synthesis of 3,5-difluoroadamantan-1-yl isocyanate from 3,5-difluoroadamantane-1 carboxylic acid and diphenylphosphoryl azide using a new fluorinating agent, Ishikawa reagent, in one stage of the synthesis. The reaction of 3,5-difluoroadamantan-1-yl isocyanate with aliphatic diamines and trans-4-[(4-aminocyclohexyl)oxy]benzoic acid afforded a series of N,N′-disubstituted ureas and bis-ureas in 43–96

The change of elastic modulus and tangent of angle of mechanical loss of materials based on polyvinyl butyral solutions in a mixture of monomers of di(1-methacryloyloxy-3-chloropropoxy-2-)methylphosphonate and 2-hydroxypropyl methacrylate has been investigated by the method of dynamic mechanical analysis. The presence of several peaks on the temperature dependences of tgd was observed, which is probably due to the presence of regions differing in crosslinking density. At 10 wt. % of polyvinylbutyral content in the process of (co)polymerization its partial migration to the surface of the formed polymeric material occurs.

The patterns of clay modification with the addition of nickel formate and the composition of polystyrene sulfonic acid with nickel formate were studied. The addition of nickel formate alone resulted in the formation of pores in the mass and on the surface of the clay, which was filled with particles containing nickel. The introduction of polystyrene sulfonic acid into the composition led to the formation of a larger number of pores on the surface of the clay and the formation of nickel-containing particles with a more developed surface.