Epoxy composite reinforced with three-dimensional polyimide fiber felt: Fabrication and tribological properties investigation

Novel epoxy (EP) composite reinforced with three-dimensional (3D) polyimide (PI) fiber felt (PI3D/EP) is first fabricated by vacuum assisted resin transfer molding. The tribological behaviors of pure EP and PI3D/EP composite under dry sliding and water lubricated condition are comparatively studied. Results indicate that both wear rates and friction coefficients of PI3D/EP composite are lower than those of pure EP. The wear resistance of PI3D/EP composite is 9.8 times higher than that of pure EP under dry sliding of 1.5 MPa and 0.76 ms(-1) while a 27-fold increase is achieved under water lubricated condition. The wear mechanisms of PI3D/EP composite are investigated based on tribological testing results and scanning electron microscopy observations. The PI fiber felt provides strong 3D structure supports to sustain most of the loads on the composite, improving the mechanical and tribological properties significantly. (c) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44160.