The introduction of combined fillers can effectively improve the mechanical and tribological properties of polytetrafluoroethylene (PTFE). In this work, three different types of nanosized fillers (zirconium dioxide, silicon dioxide, and boron nitride) were introduced in a carbon fiber-reinforced polymer matrix for the development of polymer composite materials (PCM). Tensile and compressive testing were carried out, and the hardness of created PCM was evaluated. It is shown that the compressive strength of PCM increased by 30–70%, and the hardness, increased by 38–55% compared to the initial PTFE. The tribological properties of the developed PCM were evaluated under dry friction conditions. An analysis of the results of an experimental study of wear confirmed that the inclusion of combined fillers (two- and three-component) in PTFE significantly increased wear resistance compared to the polymer matrix with a slight increase in the coefficient of friction. It has been shown that the introduction of three-component fillers has an antagonistic effect on the wear resistance of PCMs compared to two-component fillers. The thermodynamic properties of the composites were analyzed by differential scanning calorimetry and a thermomechanical analyzer. The surface morphology of polymer composites after wear testing was studied by IR spectroscopy and scanning electron microscopy to investigate and suggest a possible mechanism for increasing the wear resistance of the developed composites.

In the present study, the tribological behavior of polytetrafluoroethylene (PTFE) composites filled with natural layered silicates (LS) was investigated. The change in the morphology of the friction surface of composites depending on the content and chemical composition of layered silicates has been shown. The friction surface of PTFE composites with layered silicates was investigated by scanning electron microscopy (SEM). The formation on the friction surface of a special layer with a structure different from the bulk of the polymer, which is formed from particles of fillers and wear products, has been established. The thickness of this layer is independent of the content of layered silicates in the polymer. It was indicated that wear debris of PTFE composites was assembled during friction and uniformly cover the friction surface layer by layer, thereby forming a protective layer.

The article considers the effect of a filler based on synthetic wollastonite (CaSiO₃), which is introduced into a polymer matrix made of ultra-high molecular weight polyethylene, on the tribotechnical parameters of the produced polymer composite material. Behavioral features of composites after friction were investigated by infrared spectroscopy and scanning electron microscopy. It was found that the introduction of wollastonite into the polymer matrix contributed to a reduction in the friction coefficient by 23% and the wear rate by four times. In the micrographs of the friction surfaces of the obtained composite, the formation of new secondary structures oriented along the friction direction, different from the initial polymer matrix, was revealed. The presence of wear products (oxidized polymer groups) and CaSiO₃ on the friction surfaces was recorded by infrared spectroscopy. It was established that the synthesized CaSiO₃ particles were deformed under the action of shear forces and participated in tribochemical processes.

The aim of the study is the development of two-layer materials based on ultra-high-molecular-weight polyethylene (UHMWPE) and isoprene rubber (IR) depending on the vulcanization accelerators (2-mercaptobenzothiazole (MBT), diphenylguanidine (DPG), and tetramethylthiuram disulfide (TMTD)). The article presents the study of the influence of these accelerators on the properties and structure of UHMWPE. It is shown that the use of accelerators to modify UHMWPE leads to an increase in tensile strength of 28–53%, a relative elongation at fracture of 7–23%, and wear resistance of three times compared to the original UHMWPE. It has been determined that the introduction of selected vulcanization accelerators into UHMWPE leads to an increase in adhesion between the polymer and rubber. The study of the interfacial boundary of a two-layer material with scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) showed that the structure is characterized by the presence of UHMWPE fibrils localized in the rubber material due to mechanical adhesion.

В данной работе рассматривается влияние волластонита, синтезированного при обжиге гидросиликата кальция, полученного в модельной многокомпонентной водной системе CaCl₂–Na₂SiO₃–H₂O при температуре 20 ºС, на физико-механические свойства и структуру сверхвысокомолекулярного полиэтилена (СВМПЭ). Предложена возможность оптимизации процесса синтеза волластонита, заключающаяся во взаимодействии исходных компонентов в водном растворе при комнатной температуре. Исследование синтезированных порошков выявило формирование мелкодисперсных пористых частиц различной формы. Рентгенофазовый анализ осадка после обжига исходного продукта синтеза в интервале температур 850-1000 ºС свидетельствует об образовании волластонита триклинной модификации. Показано, что введение волластонита в полимерную матрицу приводит к существенному повышению модуля упругости на 58% и прочности при сжатии при относительной деформации 25% на 27% по сравнению с ненаполненным сверхвысокомолекулярным полиэтиленом. С использованием сканирующей электронной микроскопии установлено, что частицы волластонита способствуют трансформации надмолекулярной структуры СВМПЭ с формированием сферолитных образований меньшего размера, чем у исходного полимера. Методом ИК-спектроскопии зафиксировано наличие новых пиков, относящихся к сложноэфирной группе у композитов, содержащих волластонит. Наличие нового кислородсодержащего пика обусловлено протеканием окислительных процессов во время переработки композитов, которые активируются за счет наличия в порах волластонита адсорбированной воды и кислорода. Показано, что протекание окислительных процессов и испарение адсорбированной воды приводит к слабому межфазному взаимодействию (слабой адгезии) в граничной области между наполнителем и полимерной матрицей. Однако протекание окислительных процессов в пределах аморфной фазы обусловливает повышение жесткости материала. Методом дифференциально-сканирующей калориметрии установлено уменьшение значений энтальпии плавления и степени кристалличности при введении волластонита. Для цитирования: Данилова С.Н., Ярусова С.Б., Охлопкова А.А., Гордиенко П.С., Лазарева Н.Н. Волластонит, полученный в модельной системе CaCl₂–Na₂SiO₃–H₂O, как модификатор сверхвысокомолекулярного полиэтилена. 2023. Т. 66. Вып. 1. С. 105-113. DOI: 10.6060/ivkkt.20236601.6681.

The use of ultrasound (US) stimulated the production of composites with an improved complex of properties. It was found that ultrasonic treatment helps to reduce the coefficient of friction and improve the wear resistance of composites while maintaining deformation parameters at the level of the initial polymer. It is noted that the influence of ultrasonic vibrations on the deformation-strength characteristics of composites is due to the crystallographic properties of phlogopite and magnesium spinel (MS) used as modifiers of PTFE.