The values of molecular weight between nodes in cross-linked polyethylene obtained by the method of swelling and the method of determining the equilibrium modulus are considered. It has been shown that it is not possible to achieve uniform values of molecular weight between mesh points using these two methods. The ratio between the molecular weights located between the nodes of the network, it is proposed to call the "Shershnev coefficient".

The influence of special brands of carbon black and carbon single-wall nanotubes on the electrophysical, physico-mechanical and rheological properties of a PE-based polymer composite material is investigated.

The effect of temperature impacts on the relaxation behavior of oriented plexiglass with a linear (AO-120 brand) and with partially cross-linked (AO-120C brand) structure has been studied. The shrinkage temperatures of oriented plexiglas at complete heating of the material have been determined experimentally. The basic characteristics of organic glasses of partially cross-linked and linear structure in undirected and oriented states are studied.

The results of kinetic investigations of the orthodichlorbenzene and orthoxylene sorption by the high density polyethylene specimens of different thickness for 35 days are presented. It is shown that the sorption of solvents results in swelling of the polymer and its plasticization, which is expressed in changes in its mechanical characteristics such as ultimate strength, deformation to failure, and Young's modulus.

An express method is proposed for the analysis of the rheological characteristics of a powder lacquer at the stage of a lacquer formation during the aqueous-dispersive formation of ball powders (BP). The method uses the modified rack penetrometer and is based on the value of the yield (zero) shear stress, determined by the depth of immersion of the indenter in the plasticized polymer mass. The constants of the measuring systems (ball and conical) of the penetrometer have been established, ranging from 3.23 to 18.74, which allow determining the rheological characteristics of lacquers with a concentration of 25–50%. The discrepancy between the values obtained on a rack penetrometer and a Höppler viscometer with a pressing ball doesn’t exceed 8%, which meets the requirements of standardization documents. A rack penetrometer is recommended for operational quality control of powder lacquers in the production of BP.

It was previously shown that the polarization characteristics of the polymer, such as the polarization, the surface density of the bound charges, the intensity of the internal electric field of thermal origin, during phase transitions in an inhomogeneous temperature field are determined by the chain conformation [1]. Moreover, these characteristics can be calculated by averaging over all possible conformations of the square of the dipole moment of one macromolecule. In this work, it is shown that the dipole moment of the whole macromolecule can be expressed in terms of the dipole moment of the first monomeric unit of the macromolecule.

Raman spectroscopy, in general, is well suited for polymer studies. The sample may be in any form, including beads, films, or molded parts, and analyzed nondestructively with little or no preparation. Raman is sensitive to polymer microstructure along the backbone, crystallinity and conformation. Reliable quantitative methods are available to measure parameters such as copolymer ratios. As the popularity of confocal Raman microscopy grows, many other applications related to defect analysis, product characterization, and studies of competitive products will emerge.

The article presents methods for calculating and assessing the physical and mechanical characteristics of polymers by their of chemical structure and composition in the entire possible range of temperatures and frequencies of their use based on model concepts.

Microscopic analysis of fragments of destroyed hollow glass microspheres was used to determine the thickness of their walls. It is revealed that the wall thickness of industrial microspheres can vary significantly even within a single glass microsphere. It is shown that as the diameter of hollow glass microspheres increases, the relative wall thickness decreases, and the degree of their heterogeneity increases. The wall thickness variability leads to a significant decrease in the level of critical pressure, which causes the destruction of microspheres, compared to the calculated one.

A set of studies on the reaction extrusion of dynamically vulcanized nanocomposites based on bentonite and mixtures of random polypropylene with various brands of nitrile butadiene rubber was carried out. The influence of the temperature and pressure of the extrusion, the speed of the screw, the time of passage of the polymer mass through the material cylinder, as well as the compatibilizer, the type and concentration of the crosslinking agent on the main physicomechanical properties of dynamically vulcanized nanocomposites is established.

The properties and processing by injection molding and 3D printing of polyethylene terephthalate glycol (PET-G) filled with aluminum powder are investigated. The introduction of up to 5 vol.% of aluminum into the thermoplastic makes it possible to obtain a thermoplastic composite with a metal-like appearance, high mechanical properties and improved performance.

The effect of the method and the number of processing cycles on polypropylene thermal and physical-mechanical properties is studied. It is shown that, regardless of the processing method, the thermal stability of polypropylene, expressed by the temperature of the onset of decomposition, decreases, the content of thermally stable compounds increases, and the degree of crystallinity of the polymer decreases by 5.6–6.5%. With an increase in the number of heating-cooling cycles simulating the multiplicity of thermoplastic polypropylene processing, the temperature of the onset of decomposition decreases from 211°C to 166°C, the mass of the sample decreases due to its partial decomposition, the melting point decreases from 166°C to 158°C, the degree of crystallinity of the polymer decreases. With an increase in the number of polypropylene processing cycles by compounding in the mixing chamber of the plastograph, an increase in the load on the rotation of the screws during plasticization and in the melt flow is observed, while the strength and elongation at break of the plastic sample consistently decrease..

In this work, glycolysis of post-consumer polyethylene terephthalate with simultaneous dissolution and decomposition with a mixture of bis(2-hydroxyethyl) terephthalate and its oligomers is studied. High efficiency of this process was shown. For the glycolysis agent containing 75 wt% bis(2-hydroxyethyl) terephthalate and 25 wt% dimer and oligomers, the optimal molar ratio of the glycolysis agent units to the polyethylene terephthalate units is 5:1. On the basis of the process, a productive and cost-effective technology can be developed for the chemical destruction of post-consumer polyethylene terephthalate. A formula for calculating the bis(2-hydroxyethyl) terephthalate conversion taking into account the presence of oligomers in it is proposed.

The study of the economics of product testing was carried out on the example of three plastics processing industries - heat shrinkable films, pressure pipes and injection molded products for household needs. Methods for calculating the annual number of acceptance and periodic tests, as well as costing of various test methods, have been developed. The results of the study can be used to solve problems related to the development of the testing laboratory of the enterprise, as well as to directly attribute the testing costs to the cost of production..

The effect of temperature and high air humidity on the electrical characteristics of organosilicon adhesive sealants GPО-2 and GPО-15-3 has been investigated. Potential application of these materials as electrical insulating compounds and sealants at temperatures from -100 to 300°C has been shown.