Lithium soap: Difference between revisions
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'''Lithium soap''', |
'''Lithium soap''', a.k.a. "'''lithium grease'''" or "'''white lithium'''", is a [[soap]] made with [[lithium]] salts of [[fatty acid]]s. |
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Soaps, which act as [[surfactant|surfactant]]s, are [[salts]] of [[fatty acid]]s.<ref name="Tadros2014">{{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–}}</ref><ref name="Cahn2003">{{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–}}</ref> Sodium-based and potassium-based soaps are used as cleaning agents in domestic and industrial applications. |
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Soaps are [[salts]] of [[fatty acid]]s.<ref name="Cahn2003">{{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–}}</ref> In the domestic setting, sodium-based and potassium-based soaps are commonly used as natural cleaning [[surfactant|surfactants]]. The most useful of the non-detergent soaps are those based on lithium, as they are free of corrosive properties. For lubrication, and as form-release agents, soaps derived from lithium are used due to their higher melting points.<ref>{{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}}</ref> The main components of lithium soaps are [[lithium stearate]] and [[lithium 12-hydroxystearate]].<ref name="Chaudhuri2016">{{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–}}</ref> In addition to soap, soap-based lubricating greases also contain hydrocarbon oils and other components.<ref name=Ullmann>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}}</ref> |
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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.<ref>{{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}}</ref> |
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The main components of lithium soaps are [[lithium stearate]] and [[lithium 12-hydroxystearate]].<ref name="Chaudhuri2016">{{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–}}</ref> |
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{{unreferenced section|date=January 2019}} |
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Some formulations also include [[Polytetrafluoroethylene|PTFE]] or other substances, such as [[molybdenum disulfide]]. For high-performance and higher-temperature applications, lithium greases have been superseded by other types of lubricants.{{clarify|date=January 2013}}{{cn|date=January 2013}} |
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[[Grease (lubricant)|Lubricating greases]] are commonly formulated are mixtures of an oil and a lithium soap.<ref name=Ullmann>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}}</ref> Some formulations also include [[Polytetrafluoroethylene|PTFE]] or other substances, such as [[molybdenum disulfide]]. |
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| ⚫ | Lithium grease adheres particularly well to [[metal]], is non-[[corrosion|corrosive]], may be used under heavy loads, and exhibits good temperature tolerance. It has a [[drip temperature]] 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 [[CV joints]]. |
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==Production== |
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Lithium soaps are produced in a manner similar to [[saponification]] of triglycerides.<ref name="Tadros2014">{{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–}}</ref> However, instead of sodium hydroxide, the fatty acids are treated with [[lithium hydroxide]] or [[lithium carbonate]] to form lithium salts of fatty acids. The lithium salts are colourless solids that melt near {{convert|200|°C|°F|-1}}.<ref name=Ullmann/> |
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==References== |
==References== |
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Revision as of 11:52, 22 June 2019
Lithium soap, a.k.a. "lithium grease" or "white lithium", is a soap made with lithium salts of fatty acids.
Soaps, which act as surfactants, are salts of fatty acids.[1][2] Sodium-based and potassium-based soaps are used as cleaning agents in domestic and industrial applications.
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.[3] The main components of lithium soaps are lithium stearate and lithium 12-hydroxystearate.[4]
Lithium grease
Lubricating greases are commonly formulated are mixtures of an oil and a lithium soap.[5] Some formulations also 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 drip temperature of 190 to 220 °C (370 to 430 °F) 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 CV joints.
References
- ^ Tharwat F. Tadros (1 April 2014). An Introduction to Surfactants. De Gruyter. pp. 6–. ISBN 978-3-11-031213-3.
- ^ Arno Cahn (30 May 2003). 5th World Conference on Detergents: Reinventing the Industry : Opportunities and Challenges. The American Oil Chemists Society. pp. 182–. ISBN 978-1-893997-40-0.
- ^ The Significance of Tests of Petroleum Products: A Report. ASTM International. 1934. pp. 152–. GGKEY:FWTS3ZUUWJL.
- ^ Uttam Ray Chaudhuri (19 April 2016). Fundamentals of Petroleum and Petrochemical Engineering. CRC Press. pp. 89–. ISBN 978-1-4398-5161-6.
- ^ 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