Lithium soap#Lithium grease
{{Short description|Soap consisting of a lithium salt of a fatty acid}}
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| Examples of Lithium salts of fatty acids |
| File:Oelic Acid Lithium Salt Structural Formula V.4.svg Lithium oleate, the lithium salt of oleic acid. |
| File:Palmitic Acid Lithium Salt Structural Formula V.2.svg Lithium palmitate, the lithium salt of palmitic acid. |
| File:Stearic Acid Lithium Salt Structural Formula V.2.svg Lithium stearate, the lithium salt of stearic acid. |
Lithium soap is a soap consisting of a lithium salt of a fatty acid.{{cite book|author=Tharwat F. Tadros|title=An Introduction to Surfactants|url=https://books.google.com/books?id=CWznBQAAQBAJ&pg=PA6|date=1 April 2014|publisher=De Gruyter|isbn=978-3-11-031213-3|pages=6–}}{{cite book|author=Arno Cahn|title=5th World Conference on Detergents: Reinventing the Industry : Opportunities and Challenges|url=https://books.google.com/books?id=VMqSJROG_WYC&pg=PA182|date=30 May 2003|publisher=The American Oil Chemists Society|isbn=978-1-893997-40-0|pages=182–}} Sodium-based and potassium-based soaps are used as cleaning agents in domestic and industrial applications, whereas lithium soaps are used as components of lithium grease (white lithium).
Lithium soaps are produced by saponification of triglycerides, using lithium hydroxide or lithium carbonate as the saponification agent. Lithium soaps are used as lubricant components and form-release agents at relatively high temperatures.{{cite book|title=The Significance of Tests of Petroleum Products: A Report|url=https://books.google.com/books?id=3FkMrP4Hlw0C&pg=PA152|year=1934|publisher=ASTM International|pages=152–|id=GGKEY:FWTS3ZUUWJL}}
The main components of lithium soaps are lithium stearate and lithium 12-hydroxystearate.{{cite book|author=Uttam Ray Chaudhuri|title=Fundamentals of Petroleum and Petrochemical Engineering|url=https://books.google.com/books?id=mKQnDet5IUoC&pg=PA89|date=19 April 2016|publisher=CRC Press|isbn=978-1-4398-5161-6|pages=89–}}
Lithium grease
Lubricating greases are commonly formulated as mixtures of an oil and a lithium soap thickener.Angelo Nora, Alfred Szczepanek, Gunther Koenen, "Metallic Soaps" in Ullmann’s Encyclopedia of Industrial Chemistry 2005 Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a16_361}} Some formulations include PTFE or other substances, such as molybdenum disulfide.
Lithium grease adheres particularly well to metal, is non-corrosive, may be used under heavy loads, and exhibits good temperature tolerance. It has a dropping point of {{convert|190|to|220|°C|°F|-1}} and resists moisture, so it is commonly used as lubricant in household products, such as electric garage doors, as well as in automotive applications, such as constant-velocity joints. Lithium greases using a thickener formed by reacting a simple lithium soap with an acid are known as lithium complex greases and have higher dropping points as well as improvements to other properties.{{cite web |url=https://www.machinerylubrication.com/Read/28381/grease-lithium-production-resistance |title=Grease Selection: Lithium vs. Lithium Complex |author=David Turner |website=Machinery Lubrication |accessdate=2020-11-26 }}
References
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{{Lithium compounds}}
{{DEFAULTSORT:Lithium-Based Grease}}