Effect of mechanochemical activation of cerium dioxide on the structure and properties of polytetrafluoroethylene

As the demand for reliability and durability in polymer materials used in friction units and sealing systems continues to grow, it is essential to develop composites that exhibit enhanced tribological and mechanical properties. Polytetrafluoroethylene (PTFE) is a popular choice due to its exceptional antifriction qualities; however, its limited wear resistance restricts its application in extreme environments. To address this, we explored the modification of PTFE with cerium dioxide (CeO₂) fillers to enhance its performance. The objective of this study was to examine how the mechanochemical activation of cerium oxide influences the properties and structure of PTFE, ultimately aiming to improve its mechanical and tribological characteristics. We employed traditional processing methods for polymer composite materials (PCM) based on PTFE. The mechanochemical activation of CeO₂ was conducted using a planetary mill, and we utilized various analytical techniques, including X-ray diffraction analysis, differential scanning calorimetry, and IR spectroscopy, alongside mechanical and tribological testing to evaluate the structure and properties of the composites. Our findings revealed that incorporating 2 wt.% of CeO₂ into PTFE significantly increases the degree of crystallinity and the enthalpy of melting of the PCM when using the mechanically activated filler. Notably, tribological tests indicated a remarkable 254-fold increase in wear resistance for the PCM with mechanically activated CeO₂, while the friction coefficient remained consistent with that of the initial polymer. Additionally, IR spectroscopy analysis of the friction surfaces of the PCM indicated the formation of perfluorocarboxylate salts during wear, suggesting the occurrence of tribochemical processes. In conclusion, the developed PCM based on PTFE with mechanically activated CeO₂ demonstrates enhanced mechanical and tribotechnical properties, positioning them as promising materials for use in friction units and sealing systems.

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