Strengthening Wear Resistance of Porous Polyimide With Organic Silicon Coating

Abstract

Porous polyimide (PPI) possesses interconnected micro-pores capable of storing lubricant oil. However, the strength of PPI was weakened by pores, resulting in a decrease in wear resistance. Herein, organic silicon coating (OSC) was used to strengthen the PPI surfaces. The oil storage capacity and tribological performance of the coated PPI with varying coating coverages were investigated. Results demonstrated that PPI surfaces were effectively protected by the OSC. Particularly noteworthy was the substantial reduction in friction coefficient by 50.9 wt.% and wear rate by 55.8 wt.% observed under a high load of 100 N (103.19 MPa) with a 79.31 wt.% coating coverage. Improving surface strength and shrinking surface pore size are the two beneficial effects of the OSC. On the one hand, the OSC has high hardness and excellent density, which improves the wear resistance of PPI surfaces. On the other hand, the OSC reduces the surface pore size of PPI, improves the load-bearing capacity of the oil film, and thus reduces wear. This study provides a viable approach for strengthening the wear resistance of porous polymer materials.