Preparation and Tribological Performance of High‐Temperature‐Resistant Polyimide/ <scp> MoS ₂ </scp> Self‐Lubricating Composites

ABSTRACT This study prepares high‐temperature‐resistant polyimide/molybdenum disulfide (PI/MoS 2 ) composites via molecular structure design and composite modification, addressing bearing cage needs under extreme conditions. Rigid p ‐phenylenediamine ( p ‐PDA) is introduced into the PI backbone, raising its glass transition temperature ( T g ) to 430°C–450°C and enhancing thermal stability and mechanical strength. MoS 2 is uniformly dispersed in the PI matrix through in situ polymerization to improve interface compatibility. Friction and wear tests show that 5 wt% MoS 2 content delivers optimal lubrication at room temperature to 300°C, as its layered structure enables interlayer sliding and forms a stable transfer film for solid lubrication. The synergistic effect of rigid units and nanofillers optimizes PI's thermal stability and tribological properties, revealing related mechanisms and expanding PI's engineering applications.