Polymerization of D,L-lactide was performed in bulk at 160°C in the presence of bismuth (III) subsalicylate catalyst. Kinetics of the reaction was studied by differential scanning calorimetry in isothermal mode at 160°C and catalyst concentrations of 2500, 5000, and 7500 ppm. It was shown that the catalyst has a high activity: under this conditions an equilibrium conversion of 96% was achieved in 20–30 min, and the molecular weight of the resulting poly(D,L-lactide) reached 118 kDa.

The selective destruction of urethane and imide units in a copoly(urethane-imide) obtained on the basis of pyromellitic anhydride, 4,4′-oxydianiline, toluene-2,4-diisocyanate, polycaprolactone and containing an increased proportion of imide units was investigated. A sequential destruction was carried out, including preliminary thermolysis of the samples followed by hydrolysis of the film in solutions of potassium oxide hydrate. It is shown that in the process of chemodestruction, imide units are more labile compared to urethane units (based on polycaprolactone). As a result of chemodestruction, in the final samples, which are similar in chemical structure to poly(oxydiphenylene)pyromellitimide, urethane blocks remain in residual quantities. The characterization of the final films was carried out using the methods of TGA, DSC, DMA, AFM. The deformation-strength properties of the samples remain almost constant during the destruction processes of the copoly(urethane-imide). The results obtained are of interest in the light of the development of porous membrane materials.

Synthesis reactions and physico-mechanical, thermal properties of new aromatic copolyethersulfone ketones were studied in relation to the chemical structure of activated dihaloarenes and diols in a simpler, more economical way. It is shown that by controlling the ratio of monomers and the order of their introduction into the copolycondensation reaction, it is possible to obtain aromatic copolyethersulfone ketones with increased temperature and physicomechanical characteristics.

In this work, oligoimide powder binders of the IDA type based on 4,4’-’oxydiphthalic anhydride and bis-(4-acetamido)diphenyl oxide with different molecular weights were obtained. CFRPs were obtained by electrostatic spraying of a powdered oligoimide binder onto a carbon fabric, followed by high-temperature calendering and hot pressing of prepregs. The thermal and mechanical characteristics of the obtained carbon composites are determined.

The paper considers the standard layer-by-layer method for calculating composite structures. The main problems of the method are highlighted and the approaches which allow to simplify the calculation are analyzed. It is shown that the transition to trace can be used to restore the elastic constants of a monolayer on the basis of only one experiment. Simplified tensor transformations for rotating the coordinate system are considered. The conclusion about the limits of applicability of the simplified relations for different materials is made.

The paper presents the results of a study of the effect of the composition of PVC compound on the heat resistance of fire-retardant materials based on it. The study was carried out on the example of PVC suspension grades of different molecular weight and with different content of the plasticizer. As a result, it was shown that the heat resistance of fire-retardant materials filled with oxidized graphite is significantly affected by both the content of the plasticizer and the molecular weight of PVC. There is also a dependence of the change in the heat resistance of fire-retardant materials on the viscosity of the polymer matrix.

The purpose of the presented work is to investigate by DMA method the influence of the composition of filled and unfilled plasticized compositions based on polyvinyl acetate (PVA), polybutyl methacrylate (PBMA) and polymethyl methacrylate (PMMA) on their damping characteristics. It was found that when plasticizer is introduced into the polymer, the value of the mechanical loss coefficient first increases, reaches its maximum, and begins to decrease with further increase in the plasticizer content. The maximum effect is observed at a plasticizer/polymer volume ratio of 0.2-0.4. Two other dissipative characteristics, the temperature interval of effective damping and the integral coefficient of mechanical losses, are changing similarly. It is established that the additives of chlorinated paraffins in compositions based on PVA and PBMA can significantly improve their vibration absorbing characteristics. Introduction of mica filler into the composition of plasticized compositions based on PVA and PBMA does not lead to the appearаnсe of additional relaxation mechanisms. With increasing of the content of mica, the elastic modulus of compositions increases in the entire temperature range (especially significantly for compositions with a high content of plasticizer), the coefficient of mechanical losses slightly decreases, and the temperature practically does not change at which the maximum damping is observed.

The required functional and mechanical properties are necessary for design the polymer compositions with dispersed fillers. The mechanical properties of such polymer composition can be changed by encapsulated filler particles shell thickness varying. The paper shows that the presence of polylactide polymer shell and its thickness on the surfaces of copper (I) oxide particles significantly affect the strength of polymer composite material based on ED-20 epoxy resin. That is due to the interaction between encapsulated particles and the matrix polymer, in contrast to noncapsulated particles. In addition, a change in particle size due to increasing shell thickness also affects the strength properties of the composition. It is shown that the elastic modulus of the filled epoxy composite does not depend on the shell thickness on the particle surfaces.

Polymer-analogous transformations have been used to modify copolymers of stearyl methacrylate with maleic anhydride synthesized under radical polymerization conditions using reversible chain transfer agents of various structures. It has been established that copolymer of stearyl methacrylate with maleic anhydride modified by 25% with octanol-1 has a high depressant effect for a pour point of minus 19°С and at the same time significantly reduces both the cloud point values and the maximum filterability temperature of diesel fuel. In this regard, the obtained modified copolymers may be of interest in terms of their practical use as fuel additives.

New polyazomethines were obtained by low-temperature polycondensation of 3,3’-diaminodiphenylsulfone and aromatic dialdehydes in solution. The optimal conditions for the synthesis of polymers were found and the structure of the resulting structures was confirmed. It is shown that the synthesized polymers have sufficient manufacturability; they dissolve well in organic solvents and melt. It was found that the synthesized polyazomethines are heat-resistant polymers, and the process of their degradation proceeds in one stage. It has been established that the obtained polyazomethines exhibit thermo tropic liquid-crystal properties during melting.

The effect of inorganic additives on the ε-caprolactam with ω-dodecalactam anionic (co)polymerization process and on the properties of synthesized samples is investigated. Aluminum oxide, titanium dioxide and silicon dioxide were used as inorganic additives. It is shown that the introduction of additives at a 1 mol.% concentration at the stage of copolycaproamide synthesis contributes to a decrease in the ε-caprolactam with ω-dodecalactam anionic (co)polymerization rate. The influence of the selected additives on the physico-mechanical, thermal and operational properties complex has also been studied. It was found that the use of inorganic additives at a 1 mol.% concentration at the synthesis stage contributes to an increase in destruction temperatures compared to unmodified samples. It was found that the introduction of aluminum oxide, titanium dioxide and silicon dioxide leads to an increase in physical and mechanical parameters and Shore hardness, a decrease in water absorption and oil and gasoline resistance.

The process of tearing on trouser test pieces was studied on four types of materials according to GOST 262-93 for elastomers and according to POLYPLASTIC Group standard STO 73011750-009-2012 [3] for testing thermoplastic materials. It has been shown that when tested according to the POLYPLASTIC Group standard on materials of polyethylene group (using a tearing element), it is possible to realize an area of continuous tearing. Data on tear resistance values were obtained on four materials: plasticized PVC, polyethylene of blow molding grades, PU and silicone.

This paper presents the results of the study of a polymer filler for the “crush-core” rapid molding technology. Different formulations of the compositions, temperature regimes of curing were investigated, and the completeness of the passage of a chemical reaction under various temperature regimes was also considered. The depth of the curing reaction was separately studied in order to obtain a filler processed in a single technological cycle lasting no more than 1 hour at a temperature of 140°C, together with skins based on fiberglass prepreg.

In this paper, the effect of macropores on the mechanical characteristics during compression of thick-walled carbon fiber parts obtained by vacuum infusion has been studied. The mechanism of destruction of thick-walled carbon fiber reinforced plastic with a pore content of more than 1% under compression has been determined.

The phenomenon of double sequential neck formation during hydraulic tests of cross-linked polyethylene has been studied. It is shown that the extension ratio, formed under conditions of double neck formation at the first and second stages, varies in the range from 2 to 7.