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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 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.

The results of the study of physical and mechanical and tribological properties of PTFE-based composites with addition of serpentine and kaolin are described. Magnesium spinel was used as a functional additive. Improvement of the characteristics of the material due to mechanical activation of the fillers increasing adhesive interaction between components of the composite material was identified. Methods of capillary electrophoresis and atomic adsorption spectroscopy revealed an increase in the number of active cations due to mechanical activation. The IR-spectroscopy identified that the cause of an increase in the number of cations is destruction of octahedral networks of fillers subject to mechanical activation. It is assumed that high coordination activity of aluminum ions which are part of magnesium and kaolin spinels relative to the fluorine atoms of PTFE macromolecules and oxygen atoms on the surface of mechanically activated layered silicates, intensifies interfacial interaction.

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.