N -oleoyl sarcosine
Structural formula | |||||||||||||||||||
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Surname | N-oleoyl sarcosine | ||||||||||||||||||
other names |
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Molecular formula | C 21 H 39 NO 3 | ||||||||||||||||||
Brief description |
clear, pale yellow to reddish yellow or yellow-brown liquid |
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properties | |||||||||||||||||||
Molar mass | 353.54 g mol −1 | ||||||||||||||||||
Physical state |
liquid |
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density |
0.95 g cm −3 at 23 ° C |
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Melting point |
approx. −10 ° C |
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Vapor pressure |
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solubility |
0.44 mg · l −1 at 20 ° C, soluble in organic solvents and in mineral oil |
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safety instructions | |||||||||||||||||||
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Toxicological data | |||||||||||||||||||
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
N -Oleoylsarcosine (Sarkosyl O) is an amphiphilic oleic acid derivative with a sarcosine ( N -methylglycine) head group that is used as a water-in-oil emulsifier and corrosion inhibitor .
Occurrence and representation
A standard method for the preparation of N- acylamino acids is the Schotten-Baumann method , in which oleoyl chloride (from oleic acid and e.g. phosphorus trichloride ) is added to an aqueous solution of N -methylglycine at pH 10 (kept constant by adding sodium hydroxide solution) .
This results in largely fatty acid-free N- oleoyl sarcosine as an oil. Because of the relatively expensive production of the carboxylic acid chlorides and the expense of disposing of the phosphonic acid obtained as a by-product, the method is not suitable for industrial surfactant synthesis.
N- oleoyl sarcosine is obtained from the reaction of oleic acid with the sodium salt of sarcosine and sarcosine at 170 ° C. for 8 to 10 hours with elimination of water.
The reaction of oleic acid methyl ester (methyl oleate) with sodium sarcosinate with the addition of equimolar amounts of sodium methoxide in methanol , whereby after taking up in water, acidifying with concentrated sulfuric acid and extraction with methyl ethyl ketone Sarkosyl offers gentler conditions (120 ° C) and shorter reaction times (3.5 hours) O is obtained in 92.5% yield.
properties
N- oleoyl sarcosine is a clear, yellow to brown, viscous liquid that is sparingly soluble in water and has an acidic reaction. As a long-chain N- acyl amino acid, the surfactant is soluble in many organic solvents and in mineral oil. In the alkaline it dissolves well in water. Because of its carboxamide structure, Sarkosyl O is chemically stable even at high pH values and, as an anionic surfactant, foams strongly. N-oleyl sarcosine is not very toxic and easily biodegradable.
Applications
N- oleoyl sarcosine is a mild surfactant that irritates the skin and eyes comparatively little and therefore - together with other surface-active substances - also because of its antimicrobial and virucidal properties in personal care products, such as. B. skin cleansers is used.
The sarcosine head group of the long-chain amphiphilic N- acylamino acid is responsible for the formation of chelate- like structures during adsorption on polar and charged surfaces, e.g. B. of metals.
The molecules form oriented monomolecular films that protect the metal surface from corrosive attack.
Sarkosyl O has - especially in combination with the emulsifying and anti-corrosive active imidazoline derivative 2- (2-heptadec-8-enyl-2-imidazolin-1-yl) ethanol (Amine® O from BASF SE) is already used at low concentrations (<0.5 percent by weight) very good rust protection properties, also against non-ferrous metals such as aluminum and copper . N- oleoyl sarcosine is therefore used in anti-rust fluids and lubricating greases, fuels and lubricants, cooling lubricants such as. B. drilling and cutting oils added as a corrosion inhibitor and emulsifier .
Individual evidence
- ↑ Entry on OLEOYL SARCOSINE in the CosIng database of the EU Commission, accessed on April 20, 2020.
- ↑ Entry on N-Oleoylsarcosine at TCI Europe, accessed on May 17, 2016.
- ↑ a b c d e f g h i j Entry on oleyl sarcosine in the GESTIS substance database of the IFA , accessed on May 15, 2016 (JavaScript required)
- ↑ a b Ciba Specialty Chemicals, Ciba® Sarkosyl O: Oil soluble corrosion inhibitor ( Memento from May 30, 2016 in the Internet Archive ).
- ↑ Patent US3544606 : Process for making sarcosines. Filed on January 21, 1969 , published on December 1, 1970 , Applicant: WR Grace & Co., Inventor: JJ Singer, Jr
- ↑ a b Patent US5710295 : Preparation of alkali metal acyl amino acids. Applied June 6, 1995 , published January 20, 1998 , Applicant: Hampshire Chemical Corp., Inventor: RP Woodbury, RR Gaudette, FD Wood.
- ↑ Patent US5856538 : Preparation of N-acylamino carboxylic acids and N-acylamino sulfonic acids and their alkali metal salts. Registered on September 12, 1995 , published on January 5, 1999 , applicant: BASF AG, inventor: R. Strecker, A. Oftring, D. Hertel, G. Schuh.
- ↑ a b c Schill + Seilacher, Amino Acid Based Surfactants, Perlastan®
- ↑ Chattem Chemicals, Inc., HAMPOSYL N-Acyl Sarcosinate Surfactants
- ↑ GA Salensky, MG Cobb, DS Everhart: Corrosion inhibitor-orientation on steel . In: Ind. Eng. Chem. Prod. Res. Dev. Band 25 , no. 2 , 1986, p. 133-140 , doi : 10.1021 / i300022a002 .