One‐step preparation of carbon fiber‐ZrO2 hybrid and its enhancement on the wear‐resistant properties of polyimide.

The carbon fiber‐ZrO2(CF‐ZrO2) hybrid was prepared through one‐step hydrothermal method, which well realized the synergistic enhancement of CF and ZrO2 nanoparticles on the wear‐resistant performance of polyimide (PI) composites. Results showed that the ZrO2 nanoparticles were tetragonal and monoclinic mixed phase. The average particle size was about 10 nm. And they were in‐situ synthesized on the surface of CF, which endowed CF with much rougher surface and further improved the interfacial adhesion of PI composite. Moreover, the CF‐ZrO2 hybrid reinforced PI composite possessed higher shore hardness and thermal stability than those of PI or its composite reinforce with single CF because of CF with good compressive strength and ZrO2 with outstanding thermal property. In addition, the anti‐wear properties of the PI were greatly improved by filling CF‐ZrO2 hybrid, which was mainly because CF as the main bearing phase of the friction surface of the composites could bear most of the stresses onto the worn surface and protect the polymer matrix from severe wear in the sliding process. Meanwhile, the ZrO2 nanoparticles presented at the interface of CF and PI could not only carry the applied load, but also enhance the interfacial combination of CF with PI to form a good stress transfer and prevent the failure of CF, finally improving tribological properties of composites. Besides, the PI/CF‐ZrO2 kept reasonable friction and wear performance under high loads and rotating speeds. [ABSTRACT FROM AUTHOR]