Structure optimization of epoxy-functionalized polysiloxanes and tribological properties of the polysiloxane/molybdenum disulfide lubricating coating for low-earth orbit environment

This paper investigates applicability of polysiloxane/MoS 2 lubricating coatings in low-earth orbit (LEO). Results show that wear resistance of the polysiloxane lubricating coatings is related to R/Si value and epoxy group of the epoxy-functionalized polysiloxanes resin. The prepared polysiloxane lubricating coatings exhibited better wear resistance than existing organic coating due to the synergistic effect of low surface energy polysiloxane and MoS 2 . Furthermore, the polysiloxane coating achieved excellent AO resistance ascribe to the generation of SiO 2 protective layer. The thickness of SiO 2 layer was only 60 nm, which has no effect on vacuum tribological properties of the polysiloxanes lubricating coating. After AO irradiation, the polysiloxane lubricating coating maintained a low friction coefficient and excellent wear resistance under the vacuum condition.