The paper considers the properties of low-density spheroplastics with a polyorganosiloxane binder and a hollow glass spherical filler. The dielectric characteristics of the materials have been studied. The infl uence of the nature and ratio of the binder and filler on the electrical properties in the ultra-high frequency range has been investigated. The contribution of the organosilicon component to the characteristics of the spheroplastics is revealed. The effect of temperature on the dielectric properties of the materials is studied.

A comparative study of the effect of microwave electromagnetic fields with frequencies of 915 and 2450 MHz on changes in the structure of the damage surface during interlayer shear testing of cured carbon fiber reinforced plastic samples formed using FDM technology from composite filaments based on PEEK superstructural thermoplastic and by the vacuum infusion method based on ED-20 thermosetting resin with PEPA hardener was performed.
It was shown that regardless of the type of binder, microwave exposure helps to reduce the volume of voids formed as a result of delamination of the matrix from the filler during testing. The greatest effect (2 or more times) is achieved for the epoxy binder at a frequency of 2450 MHz. For the PEEK binder, the effect of the radiation frequency is less pronounced and in the studied temperature range it can be considered insignificant.

A complex of thermal degradation tests of PVC films stabilized with magnesium and zinc pentaerythritates, as well as stearoyl benzoylmethane, included in the formulation as a co-stabilizer, was carried out.

For the first time, data have been obtained on a single-stage synthesis of polyvinyl acetate (PVA) suspensions in the presence of oxyethylated water-insoluble organosilicon and hydrocarbon surfactants. It has been shown that in the presence of such surfactants, stable polyvinyl acetate dispersions with dispersion coefficients Dw/Dn from 0.01 to 1.15 and particle diameters from 0.25 to 0.85 microns are obtained.

The main features of the component composition of the concentrated residue from tar hydrocracking (CRTH) obtained at the TAIF-NK JSC oil refinery have been identified. The main components of CRTH are asphaltenes and resins with a total content of more than 60% by weight, which allows this residual petroleum product to be considered as a filler for the production of composite polymer materials, along with other well-known carbon materials. A comparative analysis of CRTH asphaltenes and resins using IR spectroscopy, MALDI mass spectrometry, elemental analysis, TGA, electron paramagnetic resonance, and atomic absorption spectroscopy showed their main differences from petroleum asphaltenes and resins extracted from tar. It was found that the asphaltenes and resins of CRTH differ significantly in almost all parameters compared to similar components of tar, while the asphaltenes of CRTH in this case have similar characteristics to the resins of tar. The introduction of CRTH into polyethylene and polypropylene leads to an increase in their MFI values, while changing not only rheological but also strength (decrease in strength), deformation (decrease in residual elongation) and temperature (increase in degradation temperature) properties of the resulting polymer compositions.

The effect of a hybrid filler, modified carbon nanotubes/reduced graphene oxide (MCNT/rGO), synthesized by laser ablation of a ferrocene-graphite target and graphene oxide on the properties of an elastomeric composite based on Silagerm 8030 silicone has been studied. Using Raman spectroscopy (ID/IG = 1.18–1.19) and electron microscopy, it was found that the filler consists of intertwined filamentous structures with a diameter of 30–100 nm. It is shown that the introduction of 1–4 wt.% of the MCNT/rOG hybrid leads to a synergistic improvement in functional characteristics: the time to reach a steady-state thermal regime decreased by 26% (from 142 to 105 s), and the equilibrium temperature increased by 8,3°C (from 32.2°C to 40.5°C). It has been established that the observed effect is due to the formation of a developed conductive network in a polymer matrix, where one-dimensional MCNT create long paths, and two-dimensional flakes of rOG act as conductive "bridges". The results of the work open up prospects for creating energy-efficient self-regulating systems with improved operational characteristics.

The steady-state non-isothermal process of forming a viscoelastic flat polymer film is considered. The polymer melt is extruded through a flat die subjected to uniaxial stretching and simultaneous air cooling, and then finally cooled down on a chill roll. It is assumed that the film is wide enough and the distance between the extruder head and the chill roll is small to such an extent that the change in the film width during the longitudinal stretching can be neglected. It is also assumed that the forces of gravity, inertia and surface tension can be neglected. Rheologically, the polymer melt is a viscoelastic liquid. The Upper Convected Maxwell model is used. Thermophysical properties, viscosity and relaxation time are considered to be dependent on temperature and degree of crystallinity. The mathematical model is supplemented by equations of heat balance and kinetics of non-isothermal crystallization. The problem is solved numerically using the finite difference method.

A key objective in modern materials science is the application of new materials and composites based on them. Nanocrystalline cellulose (NCC) is an object that is currently being intensively studied. This is due to the fact that NCC has a very wide range of applications due to its unique properties: high strength, small particle size, and biodegradability. Therefore, its application area is quite broad: as a reinforcing component for enhancing the mechanical properties of various polymers; in flexible electronics for the production of substrates; improving the properties of textile materials; in medicine, cosmetics, etc. In this study, the effect of a pulsed magnetic field (PMF) on the polarization, dielectric, and optical properties of NCC was studied using dielectric spectroscopy and IR spectroscopy for practical use.

The aim of this work is to optimize the synthesis conditions for polyether polyols based on recycled polyethylene terephthalate and glycerol. The effect of glycerol concentration, temperature, and duration of the alcoholysis process in the presence of a catalyst (zinc acetate) on the physical and chemical properties of the final product was studied.
The concentration of glycerol was varied from 0.4 to 4.0 mol of glycerol per 1 mol of the elementary unit of secondary PET, providing partial or complete alcoholysis, respectively. Increasing the glycerol concentration to a threshold value leads to the formation of fusible oligomers, while a higher concentration results in a liquid final product. As the concentration of glycerol increases, there is a decrease in molecular weight, ether, and acid numbers, as well as an increase in hydroxyl group concentration, indicating a deeper chemical degradation of secondary PET.
The glycerolysis temperature was increased from 180°C to 250°C, and the reaction time was increased from 6 to 30 hours. The product characteristics change non-linearly with increasing temperature: molecular weight, ether number and dynamic viscosity decrease, while the content of hydroxyl groups and acid number increase. The degree of change in all product characteristics becomes less sensitive to temperature increases.
It was found that during the first six hours, alcoholysis at 220°C leads to a decrease in the molecular weight of secondary PET, and then polycondensation occurs with the formation of aromatic polyester polyols, leading to an increase in the molecular weight, acid number and dynamic viscosity of the products. The structure of alcoholism products has been studied by IR, PMR, and NMR13C spectroscopy. It has been shown that due to the replacement of residual ethylene glycol with glycerol in the macrochain, glycerol residues are present in its composition.

The sorption properties of non-woven needle-punched fabrics made of polyethylene terephthalate, carbon-black-filled polyethylene terephthalate fibers and polyethylene terephthalate fibers with a silicone coating were studied when removing dissolved washing powder from water. It has been found that the maximum sorption capacity has a fabric made of polyethylene terephthalate fibers with a silicone coating – almost an order of magnitude greater than the sorption capacity of fabrics made of polyethylene terephthalate and carbon-black-filled polyethylene terephthalate.

A comparative physicochemical analysis of industrial aqueous suspensions of cerium oxide abrasive particles used in the processes of chemical-mechanical planarization (CMP) of plates with shallow trench isolation (CMP STI) was carried out. IR spectroscopy and dynamic light scattering showed that the cerium oxide suspension (pH ≈ 6) with an average particle size of 120 nm additionally contains polyacrylic acid (PAA) and a second non-ionic polymer, presumably polyacrylamide (PAAM), which creates conditions for electrostatic and spatial stabilization of abrasive particles. It has been shown that the transfer of the suspension (sample 1) to the acidic pH range of 3–1.5 leads to a bimodal distribution of abrasive particles by size, where, along with aggregates ranging in size from 1200 to 4000 nm, particles with a diameter of 45–30 nm appear.
The suspension (sample 2) (pH ≈ 3.5) with an average particle size of 100-120 nm does not contain polycarboxylates, and its stability is due to the presence of low molecular weight glutamic acid. Based on the known behavior of the suspensions in question in the process of CMP of STI silicon wafers, the role and mechanism of operation of the modifying additives included in them are formulated.