The influence of polytetrafluoroethylene powder on the performance of fluorosilicone grease. Fluorosilicone oil is a polysiloxane with fluorinated alkyl groups in the side chain. Fluorosilicone oil combines the advantages of silicone and organic fluorine polymers, has low surface energy and excellent solvent resistance, oil resistance, weather resistance, wear resistance, high and low temperature resistance, oxidation resistance and weather resistance, etc., making it a leader in lubricating oils.

Grease prepared with fluorosilicone oil can be used for lubrication and sealing of vacuum equipment, lubrication of conveyor belt rolling bearings, permanent lubrication of low-temperature equipment bearings, and can also be used for lubrication and sealing of parts contacting benzene solvents, lubricating oil contact hoses, gaskets, sealing rings, fuel tank linings, etc.

Fluorosilicone grease is usually made of fluorosilicone oil as raw material, solid lubricants or composite solid lubricants and suitable additives. Commonly used solid lubricants include: polytetrafluoroethylene powder, molybdenum disulfide, graphite, tungsten disulfide, etc. Among them, polytetrafluoroethylene powder has both lubrication and thickening effects, good compatibility with fluorosilicone oil, and is irreplaceable by other solid lubricants.

With the increase of the amount of polytetrafluoroethylene powder, the sintering load of fluorosilicone oil grease is greatly improved, while the anti-wear and friction reduction performance is not well improved; PTFE powder has good oil absorption capacity. The dropping point is above -200℃.
Nano- and micro-grade PTFE powders have thickening properties as thickeners for greases. There are four main differences between the two:

First, when the grease reaches the same micro-cone penetration, the amount of nano-grade PTFE powder is less than that of micro-grade PTFE powder.
Second, with the incease of the amount of nano-grade PFE powder, the friction coefficient and wear mark of the grease change very little; while with the increase of the amount of micro-grade PTFE powder, the friction coefficient and wear mark of the grease change greatly, indicating that the coarse thickener particles play an abrasive wear role.
Third, both nano-grade PTFE powder and micro-grade PTFE powder can increase the sintering load of the grease, but the more the amount added, the better; when the amount of PTFE powder added increases to a certain extent, the sintering load of the grease will not change significantly.
Fourth, the optimal mass fraction of nano-grade PTFE is 26%, and the optimal mass fraction of micro-grade PTFE is 32%.
In addition, when using fluorosilicone oil grease, other solid lubricants such as aluminum disulfide, para-polyphenylene, tungsten disulfide and graphite should be reasonably added according to actual conditions and requirements to improve its anti-friction and anti-wear properties.