Surface modification of molybdenum disulfide (MoS2) fine powder

This work reports a novel method to chemically modify the surface of molybdenum disulfide (MoS2) powder that is used as the antigalling filler in the lubricants for thread-tubing in oil pipelines. The modification by way of coupling agents effectively reduces friction and improves the antiwear and antigalling properties. The effects of three coupling agents, including KH-570, polyvinylpyrrolidone and hexadecyl cetyltrimethylammonium bromide, on particle resistance to sedimentation, powder activation index and lipophilicity are compared in detail. KH-570 on the powder improves the lipophilicity and the dispersion stability of MoS2. The modified MoS2 exhibits a much improved activation index, more than twice the original MoS2 powder. The amount of DOP absorbed by modified MoS2 powder decreases significantly. The turbidity is much higher in the modified MoS2 powders, this is in good accordance with the findings from other tests - that is, the lipophilicity has improved. The lipophilicity of the modified MoS2 increases then decreases with the increased concentration of KH-570. Overall, KH-570 outperforms the rest and is further explored for optimisation and coupling mechanism.