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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.