MoS₂ and PTFE, two competitive high performance dry lubricants for carbon fiber reinforced PPS in hydrogen compression applications

Efficient hydrogen compression is a critical component for the transition to renewable energy systems. High-pressure reciprocating piston compressors require advanced tribological solutions to ensure durability, reliability, and gas purity under dry-running conditions. Polyphenylene sulfide (PPS) polymer matrix composites, known for their excellent mechanical and thermal stability, are currently of high interest in research. This study compares the performance of molybdenum disulfide (MoS₂) and polytetrafluoroethylene (PTFE) as dry lubricants for PPS-based piston ring materials in high-pressure hydrogen environments. This work utilizes tribological and thermo-mechanical testing, along with microstructural analysis, to systematically evaluate the effects of these lubricants on friction, wear, and load-bearing capacity. Advanced imaging techniques, including synchrotron tomography, reveal the role of lubricant dispersion and interaction with PPS. The findings highlight key differences in the tribological performance of MoS₂ and PTFE, offering insights into their suitability for high-pressure hydrogen compressor applications. This research identifies promising material combinations that will significantly improve the reliability and efficiency of hydrogen compression.