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Постійне посилання на розділhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/35393
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Документ Photocurable polymer composite materials with an improved combination of strength and service properties(Scientific and technological corporation "Institute for single crystals", 2020) Avramenko, V. L.; Podhornaya, L. F.; Karandashov, O. H.This scientific paper delves into a new method of the photochemical cross-linkage of the encapsulating and adhesive materials that are based on oligoester acrylates with addition of the epoxy resin (oligomer) ER-20. The objects of research were oligocarbonate methacrylate OCM-2, epoxy oligomer ER-20 and the synthetic aluminosilicate (zeolite) filler. The additives for the photoinitiation were benzoin and its ethers. Studies the strength-, service and thermal properties of polymer composite materials (PCM) and the behavior of structural properties under different conditions. The obtained data allowed us to minimize the shrinkage of PCMs, increase their thermal oxidation stability and speed up the cross-linkage process. It was established that the combination of oligocarbonate methacrylate OCM-2 and the epoxy oligomer ER-20 has a significant effect both on the PCM cross-linkage process behavior and on its strength and service properties. The PCM composition was suggested for the encapsulation and moisture protection of the modules and assemblies of radio electronic equipment. A comparative evaluation of the suggested method of cross-linkage with the thermochemical curing allowed us to define the advantage of the photochemical method used for the material cross-linkage.Документ Investigation of the effect of structuring methods on the change in residul stresses in polymer composite material(V. N. Karazin Kharkiv National University, 2020) Cherkashina, H. M.; Avramenko, V. L.; Karandashov, O. H.The process of forming the cohesive strength of PCM is associated with a decrease in its volume. If there is no mechanical impact on the material, then this process is called shrinkage. Shrinkage occurs during cooling, when the solvent evaporates and during structuring. The free shrinkage of the PCM is hindered by its adhesive bond with the surface of the product, which is filled with a polymer compound, as a result of which more or less shrinkage stresses develop in the PCM over time. In addition to the latter in the PCM there are thermal internal stresses. Their occurrence is due to the combination of different materials in PCM, which differ significantly in the coefficients of thermal expansion. An effective way to reduce internal stresses is to add to the composition of PCM various fillers and plasticizers, what improves the relaxation properties of PCM. The aim of this work was to study the influence of different methods of structuring (polymerization), i.e. by convection and in the field of high frequency currents of epoxy, acrylic and epoxyacrylic PCM. The study of the emerging internal stresses, both shrinkage and temperature, was performed by the method of digital strain gauge, which allows not only to record the final level of residual stresses, but to monitor it in the process of structuring. The studies have shown that a more effective method of structuring is the process of structuring in the field of highfrequency current, which reduces residual stresses, increases the modulus of elasticity and forcing temperature of the studied compounds, what increases the strength and performance properties of PCM, and significantly reduces structuring time, providing uniform heating over the whole volume of PCM. It is recommended to use the obtained data in various industries related to the process of gluing and sealing both homogeneous and heterogeneous materials, as well as PCM products.Документ Study of radiation-chemical structuring of compositions based on epoxy oligomers(V. N. Karazin Kharkiv National University, 2020) Podhornaya, L. F.; Avramenko, V. L.; Karandashov, O. H.The processes of radiation-chemical structuring of modified epoxy acrylic compositions were studied depending on the nature of epoxy oligomers and modifiers. ED-20 and ED-22 grades epoxy oligomers were chosen as epoxidian oligomers; 3,4-epoxyhexahydrobenzal-3,4-epoxy-1,1-bis(hydroxymethyl)cyclohexane (UP-612 grade), 3,4-epoxycyclohexylmethyl-3,3-epoxycyclohexanecarboxylate (UP-632 grade) were chosen as cycloaliphatic oligomers; diethylene glycol diglycidyl ether (DEG) was chosen as aliphatic oligomer. To modify the epoxy oligomers, unsaturated acrylic monomers, such as acrylic acid and methyl acrylic acid ester; aromatic and aliphatic oligoester acrylates, such as α,ω-methacryl(bis-diethylene glycol)phthalate (MDP-1 grade), α,ω-methacryldi(diethyleneglycolphthalate) (MDP-2 grade), α,ω-methacryl(bis-triethyleneglycol)phthalate (MGP-9 grade) and atri-(oxyethylene)-α,ω-dimethacrylate (TGM-3 grade); condensation product of linseed oil dimerized fatty acids and polyethylenepolyamine, such as oligoamide L-20 grade; condensation product of ricinoleic acid, castor oil and maleic anhydride, such as unsaturated polyester PE-220, were used. The thermophysical and relaxation properties of cross-linked polymers, obtained under exposure to γ-radiation of Co60 and electrons accelerated by the absorbed radiation dose of 50–150 kGy at the beam current of 2-4 mA and electron energy of 240-300 keV, were studied. The distance from the exhaust window of the accelerator to the irradiated surface of the samples was 63-80 mm. The thermophysical properties of the cured polymers were evaluated using thermomechanical studies on a thermomechanograph with the temperature rise of 1о/min and the pressure of 0.54 MPa in the temperature range of 293-673 K, as well as the differential thermal and thermogravimetric analyzes on a system derivatograph by L. Paulik, R. Paulik, L. Erdei in the temperature range of 293–973 K with the rise rate of 7о/min. The relaxation properties and molecular mobility of the cross-linked polymers were studied by the dielectric method. The dielectric loss tangent was determined in the temperature range of 143-393K at the frequency of 1 kHz using a digital automatic bridge of alternating current R-589. The test sample temperature was measured using a potentiometer on a copper-constantan thermocouple, which was placed in the measuring cell along with the test sample. The samples were cooled by placing the cell in a vessel with liquid nitrogen. As a result of the studies, the influence of the chemical nature of epoxy oligomers and unsaturated modifiers on the processes of structure formation and molecular mobility of polymers, obtained under conditions of radiation-chemical curing, was established. It was determined, that when modifying epoxy oligomers with acrylic acid, methyl acrylic acid ester, oligoester acrylates of MGP-9 ((α,ω-methacryl(bistriethyleneglycol) phthalate)) or TGM-3 ((tri-(oxyethyleneglicol)-α,ω-dimethacrylate)) grades, the structuring of compositions, based on the DEG-1 aliphatic epoxy oligomer and UP-612 cycloaliphatic oligomer, was more efficient than the compositions based on unsaturated ETO oligomers grade such as 2-ethylhexylepoxytallate oligomer and epoxidian oligomers of ED-20 and ED-22 grades. It was established, that the modifier oligoamide of L-20 grade, containing primary and secondary amino groups, increased the radiation sensitivity of the compositions, based on epoxidian and cycloaliphatic oligomers, and reduced the inhibitory effect of atmospheric oxygen. The optimal composition and the main technological parameters were determined, what allowed to obtain materials with high physical and mechanical properties and adhesive strength to various metals. The application of the developed materials under industrial conditions will make it possible to organize a continuous high-speed radiation-chemical process for producing polymer coatings on metals, providing improved working conditions, lower energy consumption, as compared to the thermochemical process of the coatings production, and will increase the corrosion resistance of metals.Документ Study of influence of structurizing regims on the properties of structural glass-fiber plastics(Scientific and technological corporation "Institute for single crystals", 2018) Karandashov, O. H.; Avramenko, V. L.; Vashchenko, O. V.; Podhornaya, L. F.Manufacturing of glass-fiber articles under specified strength characteristics, different ratio of layer thickness to inner diameter and without defects and delaminations is investigated. The influence of technological regimes, degree of curing on the physical and mechanical characteristics of glass-fiber articles was studied. In order to estimate the quality of the obtained articles, and to obtain reliable data on the course of the structuring process, methods of extraction, infrared spectroscopy and differential scanning calorimetry were used.