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 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.

The paper presents the results of a study of synthetic wollastonite from boric acid production waste (borogypsum) on the physical, mechanical and tribological properties of polymer composite materials based on polytetrafluoroethylene. Wollastonite was synthesized from borogypsum by its hydrothermal treatment in alkaline medium and subsequent calcination of the obtained precipitate at 900-1000 °C for 1 h. The product with a specific surface area of 1.4 m2/g and a density of 3.06 g/cm3 obtained under the above regimes is characterized by the presence of wollastonite of triclinic modification and the presence of CaSO4 anhydrite. The wollastonite particles are needle-shaped with a needle diameter of ~100 nm. Needle-shaped wollastonite particles are shown to be interconnected and form conglomerates and agglomerates ranging in size from 10 to 70 μm. Particle agglomerates are characterized by a wide unimodal distribution of pores with a maximum of 3.78 nm with conical and slit-like shapes. It was found that the use of wollastonite results in increased wear resistance of polymer composites based on PTFE. Composites filled with 10 and 20 wt.% of wollastonite are characterized by a 700-fold decrease in the rate of mass wear relative to the initial polymer. Physical and mechanical studies of PCM show that the introduction of wollastonite increases compressive strength and modulus of elasticity. However, a decrease in strain-strength parameters was observed. Scanning electron microscopy shows the formation of secondary structures on friction surfaces, which plays a role in the adaptation of the composite to wear. The method of IR spectroscopy of friction surfaces registered the appearance of new peaks corresponding to hydroxyl, carbonyl and carboxyl compounds. This indicates a certain contribution of wollastonite particles to tribochemical processes. For citation: Danilova S.N., Tarasova P.N., Yarusova S.B., Kapitonova Yu.V., Osipova V.N., Okhlopkova A.A., Gordienko P.S. Evaluation of the influence of wollastonite from technogenic waste on the properties of a polymer composite based on polytetrafluoroethylene. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 12. P. 102-112. DOI: 10.6060/ivkkt.20246712.7064.

The wear of PTFE filled with layered silicates (LS) was investigated depending on the concentration and chemical nature of the fillers. The influence of these factors on the tribotechnical characteristics and the structure of the surface layers of composites is shown. Using SEM methods, it has been established that the introduction of LS contributes to the formation of a protective layer on the friction surface consisting of worn PTFE particles and a filler. The thickness of the layer does not depend on the concentration of LS, and the structure of the layer varies depending on the chemical composition of the fillers. It is shown that the formation of a protective layer occurs by means of worn particles clustering, uniformly covering the friction surface layer by layer.

This article investigates the influence of mechanically activated kaolinite and magnesium spinel on tribological properties and structure of polytetrafluor

This work presents the results of tribological and structural investigations of polymer composites based on polytetrafluoroethylene and muscovite. It is shown that the wear resistance of the composites increased up to 675 times in comparison with the initial polymer. The increase of wear resistance is attributed to the occurrence of tribo-oxidation processes on the friction surface, which have been confirmed by various investigations. Thus, IR spectroscopy showed that carboxylate anions are formed on the friction surface of composites during friction processes. An increase in oxygen and a decrease in carbon and fluorine concentrations on the composite surface have been detected after friction using the EDS analysis. The results of XPS have confirmed the destruction of C-F bonds and the formation of new oxygen-containing compounds. These research methods indicated the occurrence of tribo-oxidative processes during friction.