Effect of molybdenum disulphide and carbon fibers on the properties and structure of polymer composite materials based on polytetrafluoroethylene

Polymer composite materials (PCM) based on polytetrafluoroethylene (PTFE) are of great research interest due to their thermal stability, high chemical and corrosion resistance and excellent anti-friction properties. This paper presents the results of a study on the effect of carbon fibers (CF) along with molybdenum disulfide (MoS₂) with ultrasonic treatment on the mechanical and tribological properties, as well as on the structure of PTFE. Polymer composite materials were obtained according to the well-known technology for processing PTFE: the method of cold pressing and sintering. We found that ultrasonic treatment of MoS₂ is a more effective way to activate the filler compared to mechanical activation. Based on the results of physical and mechanical studies, we demonstrated that the tensile strength properties of PCM remained at the level of unfilled PTFE, the compressive stress increased by 75 %, and the hardness increased by 48 % compared to the original polymer. Structural studies have shown a fairly uniform distribution of fibers in the bulk of the polymer and isotropic reinforcement of the material. The degree of crystallinity of PCM increased by 9–11 % relative to the initial polymer. The developed composite materials are characterized by a low mass wear rate of composites by 1100 times and a low value of the friction coefficient. Microscopic studies of the friction surface of PCM revealed that hydrocarbons and MoS₂ are localized on the friction surface and protect the material from wear. The developed materials can be offered as parts in friction units, where the use of lubricating oils is limited or its use is unacceptable.

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