The resistance of polyurea coatings to the effects of a hydroabrasive medium containing 60 wt.% silicon carbide with a particle size of 1–3 mm and 40 wt.% water was studied. Experiments were carried out according to STO 52483924-001-2026. The duration of each experiment was 1 hour, the rotation speed of the samples was 400 rpm, and the dimensions of the samples were 50×50×2 mm. According to the research results, Huntsman-NMG's Extraplan-501 polyureas have the highest resistance. Polyureas produced by Khimtrust JSC also have fairly high resistance properties. The resistance of these materials exceeds the resistance of the previously studied ultra-high molecular weight polyethylene GUR 4150, polyurea Elastocoat C6335/134 and polyurethane EP MCS PT-74.

The rheological and mechanical properties of several LLDPE film grades with different structures were studied. It was shown that the rheological properties of the studied grades differ significantly in terms of effective viscosity and melt flow patterns under shear loads. The properties of films produced from the studied materials under identical conditions were compared. Film tear resistance is ambiguously related to the LLDPE structure. Films made from butene-containing LLDPE exhibit higher tear resistance values. Films made from butene-containing LLDPE have lower tensile strength values than films made from hexene-containing LLDPE. Orientation processes during film production significantly affect the film properties.

Copolymers based on polyetheretherketone (PEEK) were synthesized by nucleophilic polycondensation with the introduction of 4,4'-dichlorodiphenylsulfone (DCDPS) as a comonomer in amounts of 5, 10, and 15 mol%. The effect of potassium carbonate concentration and synthesis temperature on the polycondensation kinetics of copolymers was investigated. The structure of the obtained copolymers has been confirmed by IR spectroscopy. The effect of the amount of DCDPS and the molecular weight on such characteristics of copolymers as the degree of crystallinity, glass transition, melting, and crystallization temperatures has been studied using differential scanning calorimetry. It has been shown that varying the content of DCDPS allows for a controlled change in the degree of crystallinity of the copolymers, which opens up opportunities for targeted regulation of their technological and operational properties.

Synthesis of copolymers of acrylonitrile with n-butylacrylate for obtaining precursors of carbon fibres suitable for melt processing has been investigated by heterophase polymerisation in water and in water-alcohol mixtures. It has been shown that precipitation polymerization in water leads to the formation of copolymers that are unable to transition to a viscous state, which is probably due to their high compositional heterogeneity.
The use of water-alcohol mixtures (water/isopropanol, water/ethanol) allows equalizing the solubility of polar and low-polar monomers, which increases the uniformity of the copolymer composition. The formulation parameters (water/alcohol ratio, concentration of initiator and molecular weight regulator) have been established to obtain copolymers with a given content of n-butyl acrylate units (10–15 mol.%) and a weight-average molecular weight in the range of (20–45)×10³ g/mol.
The thermal behavior and viscoelastic properties of copolymers, including mixtures with a plasticizer (ethylene or propylene carbonate), have been studied using differential scanning calorimetry and rheometry methods. Copolymers with Mw of about 20×10³ g/mol and BA content of about 15 mol.%, obtained in a water/isopropanol system, in combination with 10–15 wt.% ethylene carbonate, have been shown to be most effective in reducing melt viscosity.
It has been found that the behavior of copolymer melts produced by heterophase polymerization differs from that of similar copolymers produced by solution polymerization and requires higher temperatures or more plasticizer to achieve flowability.

The influence of the composition of aqueous polyurethane dispersions on the hardness of composite polishing materials obtained by impregnating a non-woven needle-punched fabric made of polyethylene terephthalate fibers with a linear density of 0.33 tex with the dispersions has been studied. Additionally, the effect of change in the fabric’s volume during impregnation process on the hardness of the materials was taken into account. IMPRANIL DL 1380 (PRC) and domestic Aquapol-11 and Aquapol-21 dispersions were used. The relationships between the hardness of the composite materials and the degree of impregnation as well as the porosity coefficient have been obtained. At the same degree of impregnation, the composite materials obtained by impregnating the fabric with IMPRANIL DL 1380 dispersion (PRC) exhibit the maximum hardness. The hardness of materials depends on the mobility of the fibers of the surface layer of the fabric and composite materials. The change in the structure of the surface layer of the fabric during the impregnation process is determined by the wettability of the fibers by the polyurethane dispersions.

The effect of weak magnetic fields (less than 0.5 T) on a dielectric is known to lead to a change in the spin state of radical pairs (triplet–singlet transitions), which, in turn, intensifies the occurrence of reactions that are spin-forbidden in the initial state. This leads to a change in the supramolecular structure of polymers, resulting in changes in their crystallization and melting temperatures. The aim of this work is to experimentally verify the change in the temperature of the melt-to-crystal phase transition after exposure to a pulsed magnetic field (PMF). Using the method of recording polarization phenomena in a non-uniform temperature field, a change in the position of temperatures characterizing the crystallization and melting processes was established using the example of the crystallizing linear organosilicon polymer SKTV-1.

For the first time, the quantum chemical calculation of the 4-methylpentene-1, 4-methylhexene-1, 4,4-dimethylpentene-1 molecule in toluene was performed using the classical DFT method. Their acid strength is theoretically estimated (pKa = 30–29). It has been established that the studied olefins belong to the class of very weak H-acids (pKa > 14).

The dependence of the air permeability coefficient on the degree of impregnation of composite materials obtained by impregnating highly porous non-woven needle-punched fabric with an aqueous dispersion of polyurethane was has been studied. Samples of composite materials were obtained by impregnating the fabric without squeezing between the calender rolls. Excess dispersion was removed by free flow from the sample on a grid. The permeability coefficient increases with the degree of impregnation from 0 to 0.6 and decreases with the degree of impregnation greater than 0.6. The increase in breathability of composite materials was associated with the fixation of fibers by polyurethane particles. The structure of composite materials with impregnation degrees of 0.60 and 1.32 was studied using electron microscopy.

An overview of modern approaches to the plasticization of acrylonitrile copolymers potentially used to produce carbon fiber precursors during melt molding is presented. The main types of external plasticizers, including water-soluble polymers, lignin, and ionic liquids, are considered. The use of monomers – internal plasticizers and reactive plasticizers for the production of precursors based on (co)polymers of acrylonitrile by melt molding is discussed. The main directions of development of plasticizing systems for molten compositions of copolymers based on acrylonitrile are formulated.

The influence of single-walled and multi-walled carbon nanotubes on the structural characteristics of polymer composites based on polydimethylsiloxane (PDMS) has been determined. The study was conducted to establish the relationship between their morphology and structure and the dynamic viscosity of the resulting compositions. It was found that multi-walled carbon nanotubes can be introduced in greater quantities than single-walled ones without a significant increase in viscosity, expanding the range of technological solutions for manufacturing modes and molding methods for the composites. Single-walled nanotubes have a larger specific surface area and are longer than multi-walled nanotubes, which facilitates the formation of a more developed three-dimensional network of physical bonds between the nanotubes and polydimethylsiloxane macromolecules.

A method for obtaining unsaturated polyester resin based on recycled PETG plastic from 3D printing has been developed. The process of its curing using styrene, methyl ethyl ketone peroxide (Butanox 50M), and an accelerator (cobalt octoate) has been studied. It has been established that the physical and mechanical properties of the obtained material (breaking stress in bending up to 143 MPa, Brinell hardness of 65–92 MPa) correspond to the parameters of industrial unsaturated polyester resins. The results demonstrate the possibility of creating materials of industrial significance based on 3D printing waste.