Polyimide-based lubricating coatings synergistically enhanced by MoS2@HCNF hybrid

In this work, we report a facile and efficient approach to overcome the poor dispersion of MoS2 nanoflowers in polyimide (PI) by carefully grafting them onto the surface of hollow carbon nanofibers (HCNF). The obtained MoS2@HCNF hybrid was then utilized as homogeneous filler to enhance the tensile strength and lubricity of the PI-based protective coating. The results revealed that the tensile strength can be effectively improved by 46% accompanying with a slight decrease in elongation (19%) after the incorporation of 2.0 wt% MoS2@HCNF. Furthermore, the MoS2@HCNF/PI composite coatings also manifested outstanding anti-wear and friction reduction characteristics under the lubrication conditions of water (0.5 wt%, 72.5% reduction in wear rate) and liquid paraffin oil (1.5 wt%, 56% reduction in wear rate), demonstrating that the formed stable MoS2@HCNF hybrid could collaboratively alleviate the wear caused by the friction shear force in PI matrix through water or oil medium. The outstandingly enhanced behaviors of MoS2@HCNF hybrid suggest its potential application as the novel filler in anti-wear composite coatings.