It has been shown that the thermal conductivity of phenylon-based carbon fiber can be described within the framework of fractal analysis. Depending on the size of the core (system) of filler fibers, such a description can be obtained by applying two limiting cases: a case-specific network of resistors and a random superconducting network. It is obtained that in the case of a superconducting network, the thermal conductivity coefficient is controlled by the fractal dimension of the walk or the number of available places for this process of the core of the filler fibers.

It has been shown that a correct description of the reinforcement degree of dispersed-filled polymer microcomposites can only be obtained based on the nominal volumetric filler content, which opens the possibility of predicting this property. The reinforcing component of the structure of these composites is a combination of interfacial regions and the filler itself.

An algorithm for solving direct and reverse thermohydrodynamic tasks has been developed in order to define parameters of fluid flow, as well as specifics of working with distributed temperature measurement (DTS) data. The algorithm is demonstrated through an example of real multi-reservoir and multi-phase systems.

The article is devoted to the study of the interaction of laser radiation with polymers such as polymethylmethacrylate using the Monte Carlo method. The key physical processes that occur during this interaction, including absorption, light scattering, and heat transfer, are considered. The principles of constructing numerical models for describing light propagation in multilayer media are presented, which is important for applications in medical procedures, laser lithography, and surface treatment.

The characteristics of a modified scintillation detector based on a large NaI(Tl) crystal with a well for a quantitative method of determining the concentration of radon in the air by measuring the gamma spectra of daughter products lead and bismuth are considered in the paper. A technique is proposed to improve the energy resolution of the detector by using one FEU-173 with the installed reflective ring on the window of the NaI(Tl) crystal instead of using of the three FEU-110. Such modification makes it possible to increase the efficiency of light collection, ultimately increasing the accuracy of the quantitative method.

Using the Helmholtz equation, the orientation dependence of the dipole moments of cesium atoms adsorbed on single-crystal tungsten surfaces was calculated. It turned out that the value of the determined dipole moment depends on the position of the adatom on the crystal surface.

The autoemission characteristics of carbon films obtained by electric arc sputtering of graphite in a magnetic field were studied. Based on the analysis of the experimental Fowler-Nordheim curves, it was shown that the work function of electrons from the carbon film was ~ 0.2 eV. The current-voltage characteristics were measured at a distance of 10 μm between the carbon film surface and the anode at room temperature.

The problem of interpreting the composition of clathrate hydrates formed under conditions of incomplete thermodynamic equilibrium is considered. It is shown that in real systems, hydrate formation often occurs in nonequilibrium regimes, in which the experimentally observed compositions of the hydrate phase differ from the maximum equilibrium values. To account for the degree of completion of the phase transformation, a dimensionless disequilibrium parameter is introduced that characterizes the transition of the system from the initial to the equilibrium state of the hydrate phase.

Polylactide (PLA) is a promising biodegradable polymer widely used in 3D-printing, packaging, and biomedicine. However, its application is limited by insufficient mechanical strength and low thermal stability. This study explores the possibility of improving these properties by modifying PLA with graphene nanoparticles.

Examines the main approaches to chemical, physical, and composite modification of polyethylene, including functionalization, the creation of nanocomposites, and the use of biofillers. Modern PE waste recycling technologies are analyzed, including mechanical recycling, thermal processing (pyrolysis), and promising methods of chemical depolymerization. It is shown that integrating modification and rational recycling not only improves the material's properties but also reduces its environmental footprint. Directions for further research aimed at improving the quality of recycled polyethylene and expanding its applications are proposed.

The methods of organomodification of the basal surfaces of calcium and sodium montmorillonites by treatment with acrylate and guanidine methacrylate are considered. The influence of the chemical structure of the selected organomodifier on the physical, chemical, and operational properties of a polyolefin nanocomposite based on low-pressure polyethylene is investigated. It is established that changes in the molecular structure of the organomodified montmorillonite layer significantly affect the strength, rigidity, and elasticity of the final material. The results obtained open up prospects for the purposeful control of the properties of polymer composites, allowing the creation of materials with specified characteristics for specialized applications.

The results of studies assessing the influence of milling modes of carbon fiber reinforced plastics, including those with matrices modified with triethylene glycol dimethacrylate and siloxane vinyl-containing rubber with a platinum catalyst, on changes in their static and cyclic strength under flexural loading after exposure to conditions of low negative temperatures (–50 °С), high humidity and salt fog are presented.

The thermal behavior of ammonium polyphosphate, melamine, dipentaerythritol and mixtures based on them was studied at different component ratios. The thermal properties of ammonium polyphosphate/melamine/dipentaerythritol mixtures were found to depend on the ratio of their components. An optimal ratio of ammonium polyphosphate/melamine/dipentaerythritol components was established, at which destructive processes begin to manifest themselves at higher temperatures.

The article presents the results of a study of the complexing properties of a cationic polyelectrolyte, polydimethyldiallylammonium chloride, in relation to copper (Cu²⁺) and cobalt (Co²⁺) cations in aqueous solutions. Optimal conditions for complexation have been determined: the maximum absorption wavelengths for PDMDAAX complexes with Cu²⁺ and Co²⁺ were 715 nm and 560 nm, respectively. It has been established that the dependence of the optical density on the concentration of the reagent obeys Bouguer's law, which indicates the formation of stable complexes. The molar absorption coefficients are calculated.

Synthesis methods, structural features, physico-chemical properties, modification methods and applications of polypyrroles and polymers containing pyrrole groups are considered in detail. Special attention is paid to the prospects for further research and development of new directions in the application of these unique materials.