Study On Tribological Property Of Water Lubricated Bearing Composites With Biomimetic Microcapsule

As the core component of the ship propulsion system,the stern tube bearing has a vital role in the economic and safety of the voage.With the continuous development of water-lubricated stern tube bearing,different types of high molecular polymers are used in stern tube bearing.In the actual use process,especially in the working conditions of starting,stopping,low speed and heavy load,the polymer material has relatively serious friction and wear.Therefore,it is imperative to improve the tribological properties of the material by modifying the polymer material.In this paper,by observing the microstructure of the lignum vitae,a resin,which was covered with a shell was found inside the lignum vita and making a bionic design of this unique core-shell structure.The base oil is used as the core material,the urea-formaldehyde resin(UF)is used as the shell material,and the microcapsules are prepared by in-situ polymerization.The prepared microcapsules are blended as an additive with a high density polyethylene(HDPE)matrix material to prepare a composite material.Through the tribological test of the composite material,the test results show that adding appropriate amount of microcapsules can effectively improve the tribological properties of the material.Under the test conditions of 1.4 MPa,the wear of the composite with a microcapsule content of 3% was reduced by 82.14% compared with the pure HDPE sample.The molybdenum disulfide is used as the core material,and the UF is used as the wall material,and the microcapsule is prepared by the double emulsion method.Two different composite materials were prepared by blending molybdenum disulfide-containing microcapsules and molybdenum disulfide with a matrix material.The tribological properties of the two composites were tested to investigate the effect of molybdenum disulfide microencapsulation on the tribological properties of the materials.The test results show that the microencapsulation of molybdenum disulfide can delay the oxidation reaction in a humid environment to ensure its lubricating performance.Compared with the composite material with 10% molybdenum disulfide content,the friction coefficient of composites with 10% microcapsules decreased by 73.08%.The erucic amide(EBS)and N-N ethylene bis-stearamide are used as the core material,the urea-formaldehyde resin is used as the wall material,and the microcapsules are prepared by the double emulsion method.The prepared microcapsules are blended as an additive with a HDPE matrix material to prepare a composite material.The tribological properties of the two composites were tested to investigate the effect of the different molecular chain lengths of the two lubricants on the tribological properties of the composite.The results show that the EBS with shorter molecular chain has a higher tribological performance.The friction coefficient of the composite sample with 10% erucic amide microcapsules decreased by 66.9% compared with the HDPE sample.In summary,the microencapsulation of the lubricant can effectively delay the oxidation reaction of the lubricant.In addition,when the microcapsules are broken,the lubricant releases to the surface of the material and forms a lubricating film,thereby adding wear resistance to the material and imparts self-lubricating properties to the composite.