Tribological and rheological performance of lithium grease with poly-α-olefin and alkyl-tetralin as base oils

doi:10.1016/j.cjche.2022.07.014

Abstract

Abstract: A new category of lithium greases was synthesized by using poly-α-olefin (PAO8) and alkyl-tetralin as base oil, where the alkyl-tetralins were synthesized by the alkylation of tetralin and olefins. The influence of thickener concentration, alkyl-tetralin content and type of blend oils on the rheological and tribological performance of lithium grease was investigated. The microstructures of soap fibers were measured to reveal the structure–property correlations. The concentration of thickener and alkyl-tetralin content obviously affect the lubricating performance of lithium grease, while the molecular structure of alkyl-tetralin has no obvious impact on their properties. It was found that alkyl-tetralin could significantly enhance the thickening ability of PAO8 base oils, and decrease the amount of thickeners by 1.5% (mass). Lithium greases prepared using 20% (mass) alkyl-tetralin as co-base oil exhibited high colloidal stability, excellent rheological behaviors and tribological properties.

Key words: Lithium grease, Complexes, Rheology, Tribological properties, Preparation

摘要： A new category of lithium greases was synthesized by using poly-α-olefin (PAO8) and alkyl-tetralin as base oil, where the alkyl-tetralins were synthesized by the alkylation of tetralin and olefins. The influence of thickener concentration, alkyl-tetralin content and type of blend oils on the rheological and tribological performance of lithium grease was investigated. The microstructures of soap fibers were measured to reveal the structure–property correlations. The concentration of thickener and alkyl-tetralin content obviously affect the lubricating performance of lithium grease, while the molecular structure of alkyl-tetralin has no obvious impact on their properties. It was found that alkyl-tetralin could significantly enhance the thickening ability of PAO8 base oils, and decrease the amount of thickeners by 1.5% (mass). Lithium greases prepared using 20% (mass) alkyl-tetralin as co-base oil exhibited high colloidal stability, excellent rheological behaviors and tribological properties.

关键词: Lithium grease, Complexes, Rheology, Tribological properties, Preparation

Chen Chen, Yujie Liu, Qiong Tang, Hong Xu, Mingxing Tang, Xuekuan Li, Lei Liu, Jinxiang Dong. Tribological and rheological performance of lithium grease with poly-α-olefin and alkyl-tetralin as base oils[J]. Chinese Journal of Chemical Engineering, 2023, 56(4): 180-192.

References

[1] G. Gow, Lubricating grease, In: Chemistry and Technology of Lubricants, Springer, New York, 2010, pp. 411–432.
[2] M. Paszkowski, Assessment of the effect of temperature, shear rate and thickener content on the thixotropy of lithium lubricating greases, Proc. Inst. Mech. Eng. Part J J. Eng. Tribol. 227 (3) (2013) 209–219.
[3] M. Paszkowski, S. Olsztyńska-Janus, I. Wilk, Studies of the kinetics of lithium grease microstructure regeneration by means of dynamic oscillatory rheological tests and FTIR–ATR spectroscopy, Tribol. Lett. 56 (1) (2014) 107–117.
[4] J.B. Pan, Y.H. Cheng, J.Y. Yang, Effect of heat treatment on the lubricating properties of lithium lubricating grease, RSC Adv. 5 (72) (2015) 58686–58693.
[5] R.M. Mortier, M.F. Fox, S.T. Orszulik, Chemistry and Technology of Lubricants, Springer, Dordrecht, 2010.
[6] R. Kozdrach, The influence of base oil type on the rheological properties of ecological lubricating greases, Nafta-Gaz 77 (2) (2021) 127–135.
[7] Y. Porfiryev, S. Shuvalov, P. Popov, D. Kolybelsky, D. Petrova, E. Ivanov, B. Tonkonogov, V. Vinokurov, Effect of base oil nature on the operational properties of low-temperature greases, ACS Omega 5 (21) (2020) 11946–11954.
[8] M.R. Cai, R.S. Guo, F. Zhou, W.M. Liu, Lubricating a bright future: Lubrication contribution to energy saving and low carbon emission, Sci. China Technol. Sci. 56 (12) (2013) 2888–2913.
[9] J.B. Gajewski, M.J. Głogowski, Anti-wear additive content in fully synthetic PAO and PAG base oils and its effect on electrostatic and tribological phenomena in a rotating shaft–oil–lip seal system, J. Phys.: Conf. Ser. 418 (2013) 012045.
[10] J.E. Martín-Alfonso, A. Romero, C. Valencia, J.M. Franco, Formulation and processing of virgin and recycled polyolefin/oil blends for the development of lubricating greases, J. Ind. Eng. Chem. 19 (2) (2013) 580–588.
[11] M.A. Delgado, C. Valencia, M.C. Sánchez, J.M. Franco, C. Gallegos, Thermorheological behaviour of a lithium lubricating grease, Tribol. Lett. 23 (1) (2006) 47–54.
[12] C. Wu, K. Yang, Y. Chen, J. Ni, L.D. Yao, X.L. Li, Investigation of friction and vibration performance of lithium complex grease containing nano-particles on rolling bearing, Tribol. Int. 155 (2021) 106761.
[13] Q. He, Z.G. Wang, A.L. Li, Y.C. Guo, S.F. Liu, Tribological properties of nanometer Al₂O₃ and nanometer ZnO as additives in lithium-based grease, Ind. Lubr. Tribol. 70 (6) (2018) 953–960.
[14] J. Zhang, J.T. Li, A.L. Wang, B.J. Edwards, H.B. Yin, Z.Z. Li, Y. Ding, Improvement of the tribological properties of a lithium-based grease by addition of graphene, J. Nanosci. Nanotechnol. 18 (10) (2018) 7163–7169.
[15] A.L. Wang, J.T. Li, J. Zhang, H.B. Yin, Preparation of different-sized copper nanoparticles by reducing copper hydroxide and application in lithium-based grease, J. Nanosci. Nanotechnol. 20 (4) (2020) 2372–2381.
[16] K. Akhtar, A. Hussain, M. Gul, H. Khalid, S. Yousaf Zai, Facile synthesis of uniform calcite microcubes and their enhanced tribological performance in lithium-based commercial grease, J. Tribol. 141 (5) (2019) 052002.
[17] X.Q. Fan, W. Li, H. Li, M.H. Zhu, Y.Q. Xia, J.J. Wang, Probing the effect of thickener on tribological properties of lubricating greases, Tribol. Int. 118 (2018) 128–139.
[18] M.A. Delgado, C. Valencia, M.C. Sánchez, J.M. Franco, C. Gallegos, Influence of soap concentration and oil viscosity on the rheology and microstructure of lubricating greases, Ind. Eng. Chem. Res. 45 (6) (2006) 1902–1910.
[19] I.V. Lend'el, Y.L. Ishchuk, G.I. Cherednichenko, V.V. Sinitsyn, Dispersion media for lubricating greases, Chem. Technol. Fuels Oils 16 (5) (1980) 308–311.
[20] D. Muller, C. Matta, R. Thijssen, M.N. bin Yusof, M.C.P. van Eijk, S. Chatra, Novel polymer grease microstructure and its proposed lubrication mechanism in rolling/sliding contacts, Tribol. Int. 110 (2017) 278–290.
[21] H. Hao, Z.W. Liu, F.Q. Zhao, Y. Geng, J. Sarkis, Material flow analysis of lithium in China, Resour. Policy 51 (2017) 100–106.
[22] N. Xu, X.B. Wang, R. Ma, W.M. Li, M. Zhang, Insights into the rheological behaviors and tribological performances of lubricating grease: Entangled structure of a fiber thickener and functional groups of a base oil, New J. Chem. 42 (2) (2018) 1484–1491.
[23] T. Yang, F.J. Wang, J.P. Huang, S.D. Ling, S.L. Liu, A.G. Zhang, Y.D. Wang, J.H. Xu, Efficient continuous-flow synthesis of long-chain alkylated naphthalene catalyzed by ionic liquids in a microreaction system, React. Chem. Eng. 6 (10) (2021) 1950–1960.
[24] C. Chen, Q. Tang, H. Xu, L. Liu, M.X. Tang, X.K. Li, J.X. Dong, Alkylation of naphthalene with n-butene catalyzed by liquid coordination complexes and its lubricating properties, Chin. J. Chem. Eng. 39 (2021) 306–313.
[25] L. Li, X.R. Zhao, C. Chen, H. Xu, L. Liu, J.X. Dong, Highly selective synthesis of polyalkylated naphthalenes catalyzed by ionic liquids and their tribological properties as lubricant base oil, ChemistrySelect 4 (18) (2019) 5284–5290.
[26] S. Mazzo-Skalski, Alkylated naphthalene basestocks advance high-performance lubricants, Tribol. Lubr. Technol. 65 (2009) 38–40.
[27] T. Honda, M. Kiyozumi, S. Kojima, Alkylnaphthalene. XI. Pulmonary toxicity of naphthalene, 2-methylnaphthalene, and isopropylnaphthalenes in mice, Chem. Pharm. Bull. (Tokyo) 38 (11) (1990) 3130–3135.
[28] H. Höke, R. Zellerhoff, Metabolism and toxicity of diisopropylnaphthalene as compared to naphthalene and monoalkyl naphthalenes: A minireview, Toxicology 126 (1) (1998) 1–7.
[29] H.J. Kang, Y. Jung, J.H. Kwon, Changes in ecotoxicity of naphthalene and alkylated naphthalenes during photodegradation in water, Chemosphere 222 (2019) 656–664.
[30] L. Liu, C. Chen, Q. Tang, J.X. Dong, Preparation method and application of alkyl tetrahydronaphthalene, CN Pat., 112694379A (2021).
[31] J. Li, H. Yin, C. Zhai, A. Wang, L. Shen, Synthesis of polyphenylmethylsiloxanes and their enhancement on tribological properties of titanium complex grease, J. Appl. Polym. Sci. 136 (10) (2019) 47168.
[32] J. Zhang, A.L. Wang, H.B. Yin, Preparation of graphite nanosheets in different solvents by sand milling and their enhancement on tribological properties of lithium-based grease, Chin. J. Chem. Eng. 28 (4) (2020) 1177–1186.
[33] J.T. Li, C. Zhai, H.B. Yin, A.L. Wang, L.Q. Shen, Impact of polydimethylsiloxanes on physicochemical and tribological properties of naphthenic mineral oil (KN 4010)-based titanium complex grease, Chin. J. Chem. Eng. 27 (4) (2019) 944–948.
[34] C.J. Donahue, Lubricating grease: A chemical primer, J. Chem. Educ. 83 (6) (2006) 862.
[35] G.L. Ren, P.F. Zhang, X.Y. Ye, W. Li, X.Q. Fan, M.H. Zhu, Comparative study on corrosion resistance and lubrication function of lithium complex grease and polyurea grease, Friction 9 (1) (2021) 75–91.
[36] H. Yan, P.Y. Li, C. Duan, X.M. Dong, Studies with rheological behavior of composite lithium-based magnetorheological grease, Metals 11 (11) (2021) 1826.
[37] Z.Y. Wang, Y.Q. Xia, Z.L. Liu, The rheological and tribological properties of calcium sulfonate complex greases, Friction 3 (1) (2015) 28–35.
[38] Q.L. Yu, D.M. Li, M.R. Cai, F. Zhou, W.M. Liu, Supramolecular gel lubricants based on amino acid derivative gelators, Tribol. Lett. 61 (2) (2016) 16.
[39] B. Zakani, M. Ansari, D. Grecov, Dynamic rheological properties of a fumed silica grease, Rheol. Acta 57 (1) (2018) 83–94.
[40] J.E. Martín-Alfonso, M.J. Martín-Alfonso, C. Valencia, M.T. Cuberes, Rheological and tribological approaches as a tool for the development of sustainable lubricating greases based on nano-montmorillonite and castor oil, Friction 9 (2) (2021) 415–428.
[41] J.E. Martín-Alfonso, M.J. Martín-Alfonso, J.M. Franco, Tunable rheological-tribological performance of “green” gel-like dispersions based on sepiolite and castor oil for lubricant applications, Appl. Clay Sci. 192 (2020) 105632.
[42] M.R. Cai, Y.M. Liang, F. Zhou, W.M. Liu, Functional ionic gels formed by supramolecular assembly of a novel low molecular weight anticorrosive/antioxidative gelator, J. Mater. Chem. 21 (35) (2011) 13399–13405.
[43] L.K. Han, W.X. Niu, X.R. Zhao, H. Xu, J.X. Dong, Synthesis of layered octadecyltrimethylammonium-templated aluminosilicate and its use as a thickening agent for lubricating grease, Tribol. Lett. 70 (1) (2022) 17.
[44] N. de Laurentis, P. Cann, P.M. Lugt, A. Kadiric, The influence of base oil properties on the friction behaviour of lithium greases in rolling/sliding concentrated contacts, Tribol. Lett. 65 (4) (2017) 128.
[45] E.H. Zhang, W.M. Li, G.Q. Zhao, Z. Wang, X.B. Wang, A study on microstructure, friction and rheology of four lithium greases formulated with four different base oils, Tribol. Lett. 69 (3) (2021) 98.
[46] M.A. Delgado, M.C. Sánchez, C. Valencia, J.M. Franco, C. Gallegos, Relationship among microstructure, rheology and processing of a lithium lubricating grease, Chem. Eng. Res. Des. 83 (9) (2005) 1085–1092.
[47] B. Lin, I. Rustamov, L. Zhang, J.Q. Luo, X.N. Wan, Graphene-reinforced lithium grease for antifriction and antiwear, ACS Appl. Nano Mater. 3 (10) (2020) 10508–10521.
[48] A.S.M.A. Haseeb, S.Y. Sia, M.A. Fazal, H.H. Masjuki, Effect of temperature on tribological properties of palm biodiesel, Energy 35 (3) (2010) 1460–1464.