When processing and operating polymer materials under the influence of environmental factors (ultraviolet radiation, moisture, oxygen, ozone, etc.), a change in their properties is often observed. This research is devoted to the study of the effect of chalk additives on morphology and topography, as well as the physical and mechanical properties of samples based on recycled polypropylene raw materials after exposure to UV radiation in air. In order to confirm the occurrence of photo oxidative processes, the data of two methods were used: modified iodometric analysis and IR spectroscopy. The physical and mechanical properties of polymer composites before and after photo aging were determined on standard 1 mm thick blades. To study the surface changes of experimental polymer composites under the influence of ultraviolet radiation, atomic force microscopy was used. The result of the experiment is the proof that the chalk additive interferes with the intensive course of photo-oxidative degradation. In general, the introduction of a chalk additive in a small amount (2 to 10 weight parts) allows maintaining the strength characteristics of composites based on recycled polypropylene raw materials after exposure to UV radiation in air, probably because of crosslinking of macromolecules due to the intermolecular interaction of hydro peroxide groups accumulated by the polymer, as well as involving only surface layers of composite samples in the photo oxidation process. Moreover, the analysis of AFM images of samples subjected to ultraviolet irradiation for 18 hours shows that the surface becomes smoother. This is confirmed by the calculation of the root mean square roughness and the maximum height of the roughness. Further irradiation for additional 18 hours leads to an increase in roughness, which indicates a change in the supra molecular structure in the surface layers of polypropylene as a result of photo oxidative transformations. Therefore, from the obtained composites, one can expect the maintenance of operational characteristics during the period of consumption, followed by decomposition under the influence of environmental factors.

Recently, the development of modern technology for producing biodegradable polymers is one of the most topical issues. Filling the polymer with natural components increases the interfacial contact boundary, through which moisture and aggressive chemicals can penetrate into the material, which accelerates the decomposition of the composite in natural conditions. This study is devoted to the study of the thermophysical properties of biodegradable composite materials based on recycled polypropylene with various natural fillers of plant origin. In this work, we measured the thermal conductivity and resistivity depending on temperature, filler concentration and residence time in the recovered soil in which the samples were biodegraded, shows the relationship between the change in thermal conductivity and resistivity of the studied samples and proposed preliminary conclusions about the mechanisms of thermal conductivity of the materials considered. Adding natural fillers of plant origin to composites based on recycled polypropylene gradually increases the thermal conductivity coefficient with increasing filler content. In this case, the resistivity decreases, and, with an increase in the content of the filler, this decrease becomes more significant. This means that with an increase in conductivity, the coefficient of thermal conductivity also increases, which is typical for materials in which charge transfer occurs at the expense of electrons. As a result of destruction under the influence of the environment, the thermal conductivity of the samples decreases, and the change is most significant for samples with a high content of filler.

Abstract.1 We propose an approach to the preparation of viscoelastic systems based on chitosan without crosslinking agents. It is the formation of an additional network of physical links by introducing a low molecular weight modifier -ethanol or glycerol. It turns out that gelation of chitosan in the solution is accompanied by the formation of additional meshes of physical links, nodes or aggregates of chitosan macromolecules formed in a mixed solvent of acetic acid-water-glycerol or acetic acid-waterethanol. It promotes an earlier formation of viscoelastic properties, which eventually leads to gelation at lower polymer concentrations than in the case of chitosan solutions without alcohol additives. The resulted gelled systems are characterized by good biocompatibility, and therefore can be used as polymeric forms of drugs.

Исследовано влияние степени биодеструкции на перерабатываемость композиций на основе вторичного полипропилена в присутствии сверхвысокомолекулярного полиэтилена и растительного наполнителя-лузги подсолнечника. В результате проведенных исследований выявлено, что существует возможность повторной переработки композиций на основе вторичного полипропиленового сырья и лузги подсолнечника в присутствии сверхвысокомолекулярного полиэтилена даже после контакта с почвенными микроорганизмами в течение пяти месяцев. Также установлено, что влияние биодеструктивных процессов на показатель текучести расплава минимальное, следовательно, подходящим способом переработки композитов на основе вторичного полипропиленового сырья в присутствии сверхмолекулярного полиэтилена и лузги подсолнечника является литье под давлением.

Исследованы условия получения водорастворимых полиэлектролитных комплексов поли-N,N-диаллил-N,N-диметиламмоний хлорида и карбоксиметилцеллюлозы или сукцината хитозана и изучена их флоккулирующая способность. Флоккулирующая способность по отношению к 0.1%-й суспензии диоксида кремния растворов комплексов является более эффективной по сравнению с растворами исходными полиэлектролитов той же концентрации. Установлено, что уменьшение оптической плотности верхнего слоя дисперсии в присутствии полимерных систем по истечении 3 ч отстаивания составляет 78-80%, тогда как в присутствии индивидуальных полимеров этот показатель составляет 67 и 60% соответственно. При флоккуляции 0.1%-й суспензии диоксида кремния в присутствии комплексов с z от 0.1 до 0.3 образующийся осадок имеет больший размер флоккул, чем в присутствии индивидуальных полиэлектролитов.