A process of plastic deformation of polymer blanks based on polytetrafluoroethylene (PTFE) and a polymer composite material (PCM) based on UVIS-AK-P carbon fibers was developed to improve the strength and creep resistance of the materials. The physicomechanical and tribological properties of the composites obtained were studied and compared with those of a composite that had the same composition but was obtained using a previously developed process. It was determined that the process of plastic deformation of PTFE-based PCM and UVIS-AK-P carbon fibers is an efficient approach to obtaining high-strength wear-resistant composites with enhanced resistance to tensile load. The tensile strength tripled and the creep decreased by a factor of 22 to 29 in comparison with those of the PTFE and PCM samples not subjected to plastic deformation. Structural studies showed that this process leads to the orientation of carbon fibers (CFs) in the direction of the material flow and to the transition of the helical conformation of macromolecules to a more stable conformation, which has a favorable effect on the performance of the materials developed.

Polymer composites of a segregated network structure are dielectric polymer granules coated with electrically conductive nanoparticles at a low content, the quantity of the junctions between the granules determines the composites' mechanical properties, and the percolation network formed by the nanoparticles determines the electrical conductivity. Here, the morphology and electron‐transport properties in reduced graphene oxide (rGO)‐filled composites with a segregated structure based on polyvinyl chloride (PVC), poly(vinylidene fluoride‐co‐tetrafluoroethylene) (P(VDF‐TFE)), and ultrahigh‐molecular‐weight polyethylene (UHMWPE) are studied. Optical and electron microscopies study of the microtome‐formed cross sections have shown the morphology to be dependent on the polymer—the thinnest rGO layers are in UHMWPE‐based composites, the thicker rGO layers are in PVC‐ and P(VDF‐TFE)‐based ones. The electrical conduction of the composites and the rGO‐paper occurs through the same hopping conduction mechanisms within the wide temperature range, which allows to use the composites in applications where pure rGO is considered. Owing to thicker rGO layers open to the environment, PVC‐ and P(VDF‐TFE)‐based composites are more attractive, rather than the UHMWPE ones, in applications where layered materials are needed, for example, in lithium‐ion batteries or supercapacitors. The UHMWPE‐based composites look more promising as electrically conductive materials when mechanical strength is important.

Field exposure of polyethylene electrically conductive materials that are intended for the production of reusable containers, in which fuel is delivered to northern and arctic regions of the Republic of Sakha (Yakutia), was carried out for two years. It was shown that the developed material has the necessary climatic resistance, and its resistivity decreases, which is due to the occurrence of relaxational processes in its volume.

In the development of polymer composite materials, it is crucial to use various technological methods for introducing fillers into the structure of the base polymer, by different activation technologies of energy exposure. In this study, the processes of structure formation of polymer composite materials based on polytetrafluoroethylene and discrete hydrate cellulose carbon fibers, depending on the production technology, were investigated by scanning electron microscopy. We considered joint mechanical activation of components and passing the powder mixture through laboratory rollers. To understand the processes occurring in the friction process of the developed PCM, surface studies before and after friction by infrared spectroscopy were carried out. We found that during the friction process, depending on the friction mode, the spiral conformation of the PTFE macromolecules changes. An increase in the sliding velocity and the load during PCM friction leads to a change in the spiral conformation of macromolecules with a transition from 136 to a more stable conformation 157. We also found that the combination of technologies for joint mechanical activation of components and rolling of a powder mixture are technological techniques that can increase the structural activity of discrete hydrocarbons and intensify the adhesive interaction at the polymer-filler phase interface, which leads to an increase in the resistance of composites to creep and wear. The developed technological approaches can be used in the production of fluorocomposites containing not only carbon but also other types of fibers.

Electrically conductive composite materials based on polybenzimidazole and aromatic polyamide matrices with single-walled carbon nanotubes (SWCNTs) are studied. Composites are obtained from SWCNT dispersions in solutions of polybenzimidazole and aromatic polyamide in N-methyl-2-pyrrolidone by the same procedure. Composites based on the poly-2,2′-p-oxydiphenylene-5,5′-dibenzimidazole (OPBI) matrix with a SWCNT concentration less than 1 wt.% are shown to be not electrically conductive unlike those based on the poly-m-phenylene-isophthalamide (MPA) matrix (electrically conductive even with a SWCNT concentration of 0.1 wt.%). This feature is related to different morphologies of the composites: in OPBI-based composites, nanotubes are more effectively separated by the polymer matrix due to the π–π interaction of OPBI macromolecules with SWCNTs. The microstructure is analyzed by scanning and transmission electron microscopy. It is revealed that in the case of the OPBI- matrix, nanotubes are separate SWCNTs or bundles with a smaller diameter and a more uniform volume distribution compared to the MPA-matrix. This feature of the morphology is reflected in temperature dependences of the electrical resistance measured from room temperature down to 4.2 K. In the case of the OPBI-matrix, the electrical resistance changes more with temperature, which also indicates the better separation of SWCNTs in the OPBI- matrix than in the MPA one.

Уважаемые коллеги!Благодарим Вас за проявленный интерес к Четвертой российской конференции «Графен: молекула и 2D кристалл» и желание принять участие в её работе.Конференция проходит в научно-образовательном центре города Новосибирска -Академгородке.Мероприятие посвящено актуальным направлениям исследований и разработок в области углеродных и низкоразмерных материалов.Проведение конференции поможет координации усилий ученых в решении современных проблем материаловедения и привлечению молодых исследователей для решения актуальных научных задач.Оргкомитет выражает особую благодарность НГУ, Центру компетенций НТИ «Моделирование и разработка новых функциональных материалов с заданными свойствами», компаниям «Диаэм», «НТ-МДТ Спектрум Инструментс» и корпорации "Графеновая Долина" за финансовую поддержку и журналам Аналитика, Наноиндустрия и РЭНСИТ за информационную поддержку.Искренне надеемся, что пребывание в Новосибирском Академгородке и в стенах Новосибирского государственного университета оставит множество положительных эмоций и

The change in the properties of rubbers 98-1 and RP-10 based on nitrile butadiene rubbers with 17– 20% of acrylonitrile content under thermal cycling conditions in the range from –50 to +80°С is evaluated. The samples are exposed in the air and working hydrocarbon medium of hydraulic oil I-20A in stress-free and deformed states. It has been established that 98-1 rubber is more resistant in air and RP-10 rubber containing a sulfur-peroxide vulcanizing system and UHMWPE demonstrates high durability in a hydrocarbon medium in comparison with first one. The paper shows insignificant deformation on the rubbers properties and deterioration of the frost resistance of rubbers up to its complete loss during thermal cycling in the medium of I-20A hydraulic oil.

High-temperature composite materials comprising single-walled carbon nanotubes embedded in a polybenzimidazole (PBI) polymer matrix with a weight percentage of nanotubes from 1 to 5% were prepared and characterized. Film composite samples were prepared by flow-coating from dispersions of nanotubes in 2% PBI solution in N -methyl-2-pyrrolidone. The temperature dependences of electrical resistance of the composites were studied in the range from room temperature to 300°C in a high vacuum at a pressure less than 1 × 10 –3 Pa. The first heating cycle to 300°C gave rise to an increase in room-temperature electrical resistance of the samples due to the desorption of oxygen from the nanotubes. For the composites containing 5 and 1% nanotubes, the change was about 1.4 and 500 times, respectively. This increase was reversible: when the samples were transferred to the ambient air, the electrical resistance relaxed to its initial value. The thermal stability of the composites was proved by the repeatability of the subsequent heating cycles and by thermogravimetric analysis.

The operating conditions of products made of polymeric materials significantly affect their service life. Herein we have investigated the influence of duration of natural climatic factors of the Republic of Sakha (Yakutia) (very cold climate zone) impact on the structure and properties of polyethylene grade 273-83. IR spectroscopic studies have shown that radical oxidative reactions causing a decrease in the polymer molecular weight occur in the material during long-term natural exposure. Investigation of the melt flow index has shown that, besides the reactions accompanied by rupture of the macromolecular chains, crosslinking processes also occur in the polymer. These processes lead to a decrease in the polymer molecular weight and broadening of the molecular weight distribution. It has been shown that the change in the degree of crystallinity and the lamellas thickness is non-monotonic and is determined by the weather conditions during the exposure period. Changes in the intensity of solar radiation, as well as average daily and seasonal temperatures of the ambient air, together with chemical changes occurring in the polymer during natural exposure, lead to the appearance of areas of ordered structures in the amorphous phase, resulting in the decrease in thickness of the amorphous phase which determines the material plasticity. Therefore, the stresses in the macromolecular chains of the polymer in the amorphous phase are so much increased that the polymer exhibits the behavior of a brittle material.

Условия эксплуатации изделий из полимерных материалов оказывают существенное влияние на срок их службы. В данной статье представлены результаты исследования продолжительности воздействия естественных климатических факторов Республики Саха (Якутия) (зона очень холодного климата) на структуру и свойства полиэтилена марки 273-83. С помощью метода ИК-спектроскопии установлено, что при продолжительном натурном экспонировании в материале протекают радикальные окислительные реакции, вызывающие снижение молекулярной массы полимера. Исследование показателя текучести расплава показало, что в полимере кроме реакций, сопровождающихся разрывом макромолекулярных цепей, протекают также процессы сшивания. Оба процесса приводят к снижению молекулярной массы полимера и расширению молекулярно-массового распределения. Изменение степени кристалличности и размеров ламелярных образований имеет немонотонный характер и определяется метеоусловиями в период экспонирования. Изменения интенсивности солнечного излучения, а также среднесуточных и сезонных температур окружающего воздуха в совокупности с химическими изменениями, протекающими в полимере при натурном экспонировании, приводят к появлению областей упорядоченных структур в аморфной фазе, в результате чего толщина аморфного пространства, обусловливающего пластичность материала, снижается. При этом напряжения в макромолекулярных цепях полимера, находящихся в аморфной фазе повышаются настолько, что полимер демонстрирует поведение хрупкого материала.

Bismuth cobalt dysprosium oxide of composition Bi12.5Dy1.5CoO22.325 has been prepared by solid-state reactions. The compound has a cubic structure (space group Fm 3̅ m) with the unit cell parameter a = 0.55279(5) nm. The solution enthalpy and standard enthalpy of formation of Bi12.5Dy1.5CoO22.325 have been measured by solution calorimetry: ΔsolH0 = −1017.0 ± 7.5 kJ/mol, and ΔfH0 = −5338.8 ± 19.9 kJ/mol. The lattice enthalpy has been calculated using the Born–Haber cycle: ΔlatH0 = −99020 kJ/mol. The lattice enthalpy increases in magnitude as the lanthanide radius decreases in the neodymium–dysprosium–holmium series.

Additional methods for the investigation of polyethylene composites intended for use under the conditions of the North and the Arctic are proposed. It has been found out that the introduction of dibutyl sebacate (DBS) into pipe grade polyethylene ensures maintenance of deformation characteristics of the polymer at a sufficient level at temperatures down to minus 50 °C, as well as an increase in strength of notched specimens.

В работе исследованы композиционные электропроводящие материалы на основе матриц полибензимидазола и ароматического полиамида с одностенными углеродными нанотрубками (ОУНТ). Композиты получены из дисперсий ОУНТ в растворах полибензимидазола и ароматического полиамида в N-метил-2-пирролидоне по одинаковой методике. Показано, что композиты на основе матрицы поли-2,2’-п-оксидифенилен-5,5’-дибензимидазола (ОПБИ) при содержании ОУНТ менее 1 % (масс.) не являются электропроводящими, в отличие от композитов на основе матрицы поли-м-фенилен-изофталамида (МПА), которые являются электропроводящими даже при содержании ОУНТ 0.1 % (масс.). Данная особенность связана с различной морфологией композитов—в случае композитов на основе ОПБИ нанотрубки более эффективно разделены полимерной матрицей за счет π-π взаимодействия макромолекул ОПБИ с ОУНТ. Микроструктура исследована методами сканирующей и просвечивающей электронной микроскопии—показано, что в случае ОПБИ нанотрубки находятся в виде отдельных ОУНТ или пучков меньших по диаметру и с более равномерным распределением в объеме по сравнению с МПА. Данная особенность морфологии отражается на температурных зависимостях электросопротивления, измеренных от комнатной температуры до 4.2 К. В случае ОПБИ-матрицы электросопротивление заметно сильнее изменяется с температурой, что также свидетельствует о лучшем разделении ОУНТ в матрице ОПБИ по сравнению с МПА.

A comparative analysis of hot pressing and extrusion for obtaining polymer composite materials based on UHMWPE was carried out. The paper describes physical-mechanical and tribological studies of the developed composite materials. It was found that samples obtained by extrusion have high wear resistance and significantly better deformation and strength properties compared to samples obtained by hot pressing. On the basis of the performed studies, the possibility of processing composites based on UHMWPE by extrusion by adding a low-viscosity grade of PE and stearic acid has been shown.

The effect of vulcanization system on the properties of polymer-elastomer composite materials based on nitrile-butadiene rubber and ultrahigh molecular weight polyethylene is studied. An analysis of the rheometric and vulcanization characteristics of rubber compounds shows that, in the case of combined sulfur-peroxide vulcanization system, the crosslinking density of vulcanizates increases considerably. The study of the elastic and strength behavior and dynamic mechanical properties of the vulcanizates demonstrates that the sulfur-peroxide vulcanization system provides the best parameters, in particular at low temperatures. An examination of elastic and hysteresis properties of the samples before and after vulcanization, which are measured under dynamic loading in a wide frequency and strain range, allows one to describe the features of physicochemical interactions in polymer-elastomer materials depending on the used vulcanization system. The supramolecular structure of the vulcanizates is visualized by scanning electron microscopy, and chemical interaction between macromolecules of nitrile-butadiene rubber and ultrahigh molecular weight polyethylene occurring during peroxide vulcanization is proved by IR spectroscopy.

Electron transport in composites based on dielectric polymer of polybenzimidazole and single-walled carbon nanotubes (SWCNTs) has been studied. The composites were synthesized by flow coating of dispersions (colloidal systems) of SWCNTs in solutions of polybenzimidazole in N-methyl-2-pyrrolidone. Concentration of SWCNTs in the composites was 1, 2, and 3 % (wt.). Electron transport in the film samples of the composites was studied by measuring and analyzing temperature dependences of the electrical resistance of the composites in the range from cryogenic temperature to 300 °C. It was shown that the higher SWCNTs concentration the weaker the dependences were. That is most likely due to a more significant contribution of metallic SWCNTs to the conductivity and weaker dependences correspondingly.

The development of new functional materials for electronics is associated with a large number of experimental studies, often routine, aimed at determining the performance characteristics and properties of such materials. And in order to accelerate such researches, process automation is required. The article describes a method for automating an experimental setup for studying the piezoresistive effect in film polymer composite materials with a large number of loading cycles of the compression-tension type. The program was written in Python and Arduino C (based on C++). Due to the large open Python community and many libraries, it was possible to develop an experimental installation application with various functionality. The results of automation were verified by measuring strain-sensing properties of polymer composite based on polybenzimidazole matrix with few-layered graphene. The program allows to conduct any multi-day experiment with slow measurement loading cycles and fast intermediate (up to 10 7 and even more) ones, which speeds up researches.

Traditionally, the method of liquid extraction is used to extract metals from aqueous. This work is devoted to the combination of perspective alternative for hazardous solvents (aqueous two-phase systems based on water-soluble polymers) and the novel deep eutectic solvents in the non-ferrous metals extraction processes. In this work, the synthesis of deep eutectic solvent based on a water-soluble polymer (PPG-425) and tetrabutylammonium bromide (TBAB) by stirring for 10 minutes at 80° C has been shown. The obtained results showed not only the possibility of using DES in the metal extraction process, but the selectivity to the Fe(III) and Zn(III), the distribution coefficients were 71.64 and 25.17 respectively. The metal concentrations were determined spectrophotometrically using 4-(2-pyridylazo)resorcinol. This work shows the perspectives of using DESs in the metal extraction processes.