Tribological Performance of Phosphonium Ionic Liquids as Additives in Lithium Lubricating Grease
Abstract
:1. Introduction
2. Experimental Section
2.1. Synthesis and Characterization of the Ionic Liquids
2.2. Preparation of the Lithium Greases
2.3. Characterization of the Lithium Greases
3. Results and Discussion
3.1. Physical Properties of the Lithium Greases
3.2. Rheological Properties
3.3. Tribological Properties
3.4. Surface Analysis
4. Conclusions
- (1)
- The [P88814][DEHP] grease showed a higher dropping point than the PAO 10 grease, and the dropping point of the [P888p][DEHP] grease and the [P88814][AOT] grease is lower than that of the PAO 10 grease. All of the lubricating greases are noncorrosive to copper.
- (2)
- Compared with the PAO 10 grease, the values of the linear viscoelasticity modulus of the [P88814][DEHP] and [P88814][AOT] greases decreased. However, the same values of the linear viscoelastic functions were found for the [P888p][DEHP] grease.
- (3)
- The ILs were found to be effective lubricant additives for improving the friction-reducing and antiwear properties and the maximum non-seizure load (PB values) of PAO 10 lithium lubricating grease. A surface analysis showed that a tribochemical film was generated from the ILs to reduce friction and wear.
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Onset Decomposition Temperature (°C) | Density (g/mL, 25 °C) | Kinematic Viscosity (cSt) | ||
---|---|---|---|---|
40 °C | 100 °C | |||
PAO 10 | 225 | 0.83 ± 0.03 | 70.1 ± 0.5 | 10.4 ± 0.7 |
[P88814][DEHP] | 310 | 0.94 ± 0.05 | 803 ± 3 | 93.7 ± 1 |
[P888p][DEHP] | 273 | 0.93 ± 0.02 | 4586 ± 2 | 218 ± 3 |
[P88814][AOT] | 273 | 0.92 ± 0.03 | 664 ± 2 | 55.4 ± 0.9 |
Lubricating Greases | Poly Alpha Olefin 10 | [P88814][DEHP] | [P888p][DEHP] | [P88814][AOT] |
---|---|---|---|---|
Dropping point (°C) | 334 ± 1 | 355 ± 5 | 295 ± 1 | 213 ± 3 |
Penetration (1/4 mm) | 73 ± 1 | 78 ± 1 | 75 ± 1 | 69 ± 1 |
Copper corrosion (100 °C, 24 h) | 1a | 1a | 1a | 1a |
C (At%) | O (At%) | P (At%) | S (At%) | Fe (At%) | |
---|---|---|---|---|---|
PAO 10 | 8.07 | 15.83 | - | - | 58.46 |
ZDDP | 30.96 | 11.09 | 0.09 | - | 57.81 |
[P88814][DEHP] | 20.18 | 14.68 | 0.56 | - | 64.58 |
[P888p][DEHP] | 13.01 | 9.37 | 1.25 | - | 76.37 |
[P88814][AOT] | 23.37 | 7.49 | 0.17 | 1.35 | 67.61 |
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Wang, Z.; Chang, J.; Cai, C. Tribological Performance of Phosphonium Ionic Liquids as Additives in Lithium Lubricating Grease. Lubricants 2018, 6, 23. https://doi.org/10.3390/lubricants6010023
Wang Z, Chang J, Cai C. Tribological Performance of Phosphonium Ionic Liquids as Additives in Lithium Lubricating Grease. Lubricants. 2018; 6(1):23. https://doi.org/10.3390/lubricants6010023
Chicago/Turabian StyleWang, Zeyun, Jun Chang, and Chao Cai. 2018. "Tribological Performance of Phosphonium Ionic Liquids as Additives in Lithium Lubricating Grease" Lubricants 6, no. 1: 23. https://doi.org/10.3390/lubricants6010023