The work is devoted to the study of the effect of an aqueous medium on a polymeric biodegradable material based on poly-3- hydroxybutyrate (PHB) by differential scanning calorimetry (DSC). To analyze the structural reorganizations of the polymer, we studied the effect of an aqueous medium on the process of polymer crystallization after soaking in distilled water. It is shown that after exposure to water, the forms of crystallization exotherms change, the rate of polymer crystallization decreases, and the heat of the process decreases insignificantly. To analyze the kinetics of non-isothermal crystallization, we used the kinetic crystallization parameter G [deg/min], which characterizes the rate of polymer crystallization in the non-isothermal mode. It has been established that the crystallizability of PHB decreases after exposure of the samples. The observed dependence of the parameter G on the scanning rate indicates a decrease in the mobility of polymer chains, a decrease in their flexibility after exposure to an aqueous medium, which is a consequence of a change in their structure.

The paper presents data on the effect of the type of structure and processing method (rolling and extrusion) on the density of particulate-filled polymer composite materials (DFPCM) and the destruction of hollow glass spheres in a low-density polyethylene matrix.

To obtain light DNPCM, we recommend using PSMS with a density of 0.30 g/cm³ (MS-VP-A9(4) with the SNS-1 structure type and the Θ parameter from 0.50 to 0.60 vol. use a twin-screw extruder The density of particulate-filled composite materials in this case is 0.72-0.75 g/cm³, and the weight reduction is ~ 18-21% relative to the original LDPE.

The results of a comparative analysis of the properties and characteristics of polyphenylene sulfides of foreign and experimental domestic production are presented.

The regularities of radical copolymerization of methoxyoligo(ethylene glycol)methacrylate (MOEGM) with an ethoxylation degree of 11 and methoxyoligo(propylene glycol)methacrylate (MOPGM) with a propoxylation degree of 6 or 10 in toluene solutions were determined. The copolymers formed at low degrees of conversion are enriched with ethoxylated ether units in both pairs of monomers. The relative activities of the comonomers determined by the Fineman-Ross methods are in the range of 1.36–1.88 (MOEGM) and 0.56–0.92 (MOPGM). It has been established that the activity of MOPGM decreases with an increase in the length of the oligopropylene glycol chain.

The rheological properties of compositions based on HDPE with the addition of chalk concentrate and linear low-density polyethylene (LLDPE), as well as the thermal stability of the investigated compositions, were studied by capillary viscometry and DSC. It is shown that the introduction of chalk concentrate with chalk content of 80 wt.% into HDPE sharply reduced the compositions thermal stability and changed the compositions flow character. The addition of LLDPE to chalk-filled HDPE resulted in a decrease in the effective viscosity and an increase in the thermal stability of the compositions.

A comparative study of the characteristics of two fiber-filled molding materials, which include a discrete carbon viscose fiber as a filler and phenol-formaldehyde resins of the novolac or resol type as a binder, is given. The DTA-DTG characteristics of the initial resins and the physico-mechanical properties of carbon fiber blanks obtained from fiber-filled molding materials of these types by hot compression molding were determined. It has been established that, regardless of the type of phenol-formaldehyde resin, the density, strength characteristics, toughness and thermal conductivity of carbon fiber plastics based on various resins are practically the same. A comparison of the microstructure of the obtained carbon fiber plastics based on various resins showed that in the case of using phenol-formaldehyde resin of the novolac type, a higher degree of orientation of the fiber filaments parallel to the pressing plane is achieved, which is associated with greater fluidity of the initial fiber-filled molding material. In the direction perpendicular to the pressing axis, the chaotic orientation of the fiber filaments is realized.

The influence of the content of ash from the processing of municipal waste in polypropylene on the dependence of the specific volume on temperature, the glass transition temperature, the change in the «free» and «occupied» specific volumes, and the mechanism of crystallization of nanocomposites based on them have been studied.

The transfer of mixtures of hexane and toluene in thermoplastic polyurethanes used in the production of tanks for temporary storage and transportation of liquid fuels has been investigated. The standard methodology for estimating the diffusion permeability of polymers is not the basis for modeling the natural loss of fuels during storage. A model for estimating natural loss is proposed, the equations of which describe the linear dependences of the decrease in the mass of fuels in tanks in the coordinate of a conditional time equal to the square root of time. The efficiency of the proposed model depends on the composition of the hexane-toluene mixture, since the composition of the mixture affects the limiting stage of the process, which determines the dependence of the natural loss either on the diffusion rate of the fuel in the tank shell, or on the volatilization of the released fuel from the outer surface of the tank.

In this paper, the process of technological design of small-sized carbon fiber parts with complex geometry used in the design of unmanned aerial vehicles is considered. Approaches to the placement of splicing points in preform layers are presented. Regularities have been established that relate the number and location of splicing points in the reinforcing layers of carbon fiber reinforced composite and its mechanical characteristics.

The question of the efficiency of turning processing of thermoplastic polymer materials with cutting ceramics is considered. The fact of a decrease in the values of the cutting force when turning the investigated thermoplastics with a tool made of ceramic material KNT16 was experimentally established. It has been experimentally proven that turning caprolon and fluoroplastic using a KNT16 cermet cutting insert leads to the formation of a supramolecular structure of a high degree of homogeneity.

The paper identifies and analyzes problematic issues of identification of linear polyethylene and their significance for the production of packaging films with the required functional characteristics.

It is shown that the adhesive bonding of microfluidic chips made of polymethylmethacrylate, bonded with domestic glues SM Chemie 301 and SM Chemie 700, withstand pressure up to 0.3 MPa (1 hour), as well as dynamic loads arising from repeated temperature changes from 60 to 95°C. These adhesives do not inhibit the polymerase chain reaction and can be recommended for bonding microfluidic chips for this method of molecular diagnostics.

The fact of increasing the elasticity of polyethylene gas pipelines in the process of long-term aging has been found. resumably, the increase in elasticity is due to the accumulation of mercaptans present in natural gas in the wall of the polyethylene pipe. It is shown that a specific mechanism for increasing elasticity during long-term operation consists in creating conditions for the development of secondary necking.