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Alkylbenzene sulfonate

January 01, 1970

Alkylbenzene sulfonates are a class of anionic surfactants, consisting of a hydrophilic sulfonate head-group and a hydrophobic alkylbenzene tail-group. Along with sodium laureth sulfate, they are one of the oldest and most widely used synthetic detergents and may be found in numerous personal-care products (soaps, shampoos, toothpaste etc.) and household-care products (laundry detergent, dishwashing liquid, spray cleaner etc.).[1] They were introduced in the 1930s in the form of branched alkylbenzene sulfonates (BAS). However following environmental concerns these were replaced with linear alkylbenzene sulfonates (LAS) during the 1960s.[2] Since then production has increased significantly from about one million tons in 1980, to around 3.5 million tons in 2016, making them most produced anionic surfactant after soaps.[citation needed]

The general structure of Sodium dodecylbenzenesulfonates, prominent examples of alkylbenzene sulphonates

Branched alkylbenzene sulfonates edit

 
An example of a branched alkylbenzene sulfonate (BAS)
 
Extensive foaming Fremont, California - 1972

Branched alkylbenzene sulfonates (BAS) were introduced in the early 1930s and saw significant growth from the late 1940s onwards,[3] in early literature these synthetic detergents are often abbreviated as syndets. They were prepared by the Friedel–Crafts alkylation of benzene with 'propylene tetramer' (also called tetrapropylene) followed by sulfonation. Propylene tetramer being a broad term for a mixture of compounds formed by the oligomerization of propene, its use gave a mixture of highly branched structures.[4]

Compared to traditional soaps, BAS offered superior tolerance to hard water and better foaming.[5] However, the highly branched tail made it difficult to biodegrade.[6] BAS was widely blamed for the formation of large expanses of stable foam in areas of wastewater discharge such as lakes, rivers and coastal areas (sea foams), as well as foaming problems encountered in sewage treatment[7] and contamination of drinking water.[8] As such, BAS was phased out of most detergent products during the 1960s, being replaced with linear alkylbenzene sulfonates (LAS), which biodegrade much more rapidly. BAS is still important in certain agrochemical and industrial applications, where rapid biodegradability is of reduced importance. For instance, inhibiting asphaltene deposition from crude oil.

Linear alkylbenzene sulfonates edit

 
An example of a linear alkylbenzene sulfonate (LAS)

Linear alkylbenzene sulfonates (LAS) are prepared industrially by the sulfonation of linear alkylbenzenes (LABs), which can themselves be prepared in several ways.[2] In the most common route benzene is alkylated by long chain monoalkenes (e.g. dodecene) using hydrogen fluoride as a catalyst.[9] The purified dodecylbenzenes (and related derivatives) are then sulfonated with sulfur trioxide to give the sulfonic acid.[10] The sulfonic acid is subsequently neutralized with sodium hydroxide.[1] The term "linear" refers to the starting alkenes rather than the final product, perfectly linear addition products are not seen, in-line with Markovnikov's rule. Thus, the alkylation of linear alkenes, even 1-alkenes such as 1-dodecene, gives several isomers of phenyldodecane.[11]

Structure property relationships edit

Under ideal conditions the cleaning power of BAS and LAS is very similar, however LAS performs slightly better in normal use conditions, due to it being less affected by hard water.[12] Within LAS itself the detergency of the various isomers are fairly similar,[13][14] however their physical properties (Krafft point, foaming etc.) are noticeably different.[15][16] In particular the Krafft point of the high 2-phenyl product (i.e. the least branched isomer) remains below 0 °C up to 25% LAS whereas the low 2-phenyl cloud point is ~15 °C.[17] This behavior is often exploited by producers to create either clear or cloudy products.

Environmental fate edit

The biodegradability of alkylbenzene sulfonates has been well studied,[6][18][19] and is affected by isomerization, in this case, branching. The salt of the linear material has an LD50 of 2.3 mg/liter for fish, about four times more toxic than the branched compound; however the linear compound biodegrades far more quickly, making it the safer choice over time. It is biodegraded rapidly under aerobic conditions with a half-life of approximately 1–3 weeks;[18] oxidative degradation initiates at the alkyl chain.[1] Under anaerobic conditions it degrades very slowly or not at all, causing it to exist in high concentrations in sewage sludge, but this is not thought to be a cause for concern as it will rapidly degrade once returned to an oxygenated environment.

References edit

  1. ^ a b c Kurt Kosswig,"Surfactants" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, 2005, Weinheim. doi:10.1002/14356007.a25_747
  2. ^ a b Kocal, Joseph A; Vora, Bipin V; Imai, Tamotsu (November 2001). "Production of linear alkylbenzenes". Applied Catalysis A: General. 221 (1–2): 295–301. doi:10.1016/S0926-860X(01)00808-0.
  3. ^ Dee, Foster; Snell, Cornelia T. (August 1958). "50th ANNIVERSARY FEATURE—Fifty Years of Detergent Progress". Industrial & Engineering Chemistry. 50 (8): 48A–51A. doi:10.1021/ie50584a005.
  4. ^ Scheibel, Jeffrey J. (17 December 2015). "The evolution of anionic surfactant technology to meet the requirements of the laundry detergent industry". Journal of Surfactants and Detergents. 7 (4): 319–328. doi:10.1007/s11743-004-0317-7. S2CID 93889318.
  5. ^ Hill, J. A. (22 October 2008). "The Chemistry and Application of Detergents". Journal of the Society of Dyers and Colourists. 63 (10): 319–322. doi:10.1111/j.1478-4408.1947.tb02430.x.
  6. ^ a b Hashim, M. A.; Kulandai, J.; Hassan, R. S. (24 April 2007). "Biodegradability of branched alkylbenzene sulphonates". Journal of Chemical Technology & Biotechnology. 54 (3): 207–214. doi:10.1002/jctb.280540302.
  7. ^ McKinney, Ross E. (1957). "Syndets and Waste Disposal". Sewage and Industrial Wastes. 29 (6): 654–666. JSTOR 25033358.
  8. ^ Sawyer, Clair N.; Ryckman, Devere W. (1957). "Anionic Synthetic Detergents and Water Supply Problems". American Water Works Association. 49 (4): 480–490. Bibcode:1957JAWWA..49d.480S. doi:10.1002/j.1551-8833.1957.tb16814.x. JSTOR 41254845.
  9. ^ Cahn, AOCS]. Ed.: Arno (2003). 5th World Conference on Detergents: Reinventing the industry - opportunities and challenges ([Elektronische Ressource] ed.). Champaign, Ill.: AOCS Press. ISBN 1-893997-40-5.
  10. ^ Roberts, David W. (May 1998). "Sulfonation Technology for Anionic Surfactant Manufacture". Organic Process Research & Development. 2 (3): 194–202. doi:10.1021/op9700439.
  11. ^ Bipin V. Vora; Joseph A. Kocal; Paul T. Barger; Robert J. Schmidt; James A. Johnson (2003). "Alkylation". Kirk-Othmer Encyclopedia of Chemical Technology. doi:10.1002/0471238961.0112112508011313.a01.pub2. ISBN 0471238961.
  12. ^ Matheson, K. Lee (August 1985). "Detergency performance comparison between LAS and ABS using calcium sulfonate precipitation boundary diagrams". Journal of the American Oil Chemists' Society. 62 (8): 1269–1274. doi:10.1007/BF02541841. S2CID 98677989.
  13. ^ Matheson, K. Lee; Matsoim, Ted P. (September 1983). "Effect of carbon chain and phenyl isomer distribution on use properties of linear alkylbenzene sulfonate: A comparison of 'high' and 'low' 2-phenyl LAS homologs". Journal of the American Oil Chemists' Society. 60 (9): 1693–1698. doi:10.1007/BF02662436. S2CID 97659271.
  14. ^ Baumgartner, F. N. (June 1954). "Relation of Molecular Structure to Detergency of Some Alkylbenzene Sulfonates". Industrial & Engineering Chemistry. 46 (6): 1349–1352. doi:10.1021/ie50534a061.
  15. ^ Drozd, Joseph C.; Gorman, Wilma (March 1988). "Formulating characteristics of high and low 2-phenyl linear alkylbenzene sulfonates in liquid detergents". Journal of the American Oil Chemists' Society. 65 (3): 398–404. doi:10.1007/BF02663085. S2CID 93127857.
  16. ^ Sweeney, W. A.; Olson, A. C. (December 1964). "Performance of straight-chain alkylbenzene sulfonates (LAS) in heavy-duty detergents". Journal of the American Oil Chemists' Society. 41 (12): 815–822. doi:10.1007/BF02663964. S2CID 98586085.
  17. ^ Farn, Richard J. (2006). Chemistry and technology of surfactants. Oxford: Blackwell Pub. p. 96. ISBN 978-14051-2696-0.
  18. ^ a b Jensen, John (February 1999). "Fate and effects of linear alkylbenzene sulphonates (LAS) in the terrestrial environment". Science of the Total Environment. 226 (2–3): 93–111. Bibcode:1999ScTEn.226...93J. doi:10.1016/S0048-9697(98)00395-7. PMID 10085562.
  19. ^ Mackay, Donald; Di Guardo, Antonio; Paterson, Sally; Kicsi, Gabriel; Cowan, Christina E.; Kane, David M. (September 1996). "Assessment of chemical fate in the environment using evaluative, regional and local-scale models: Illustrative application to chlorobenzene and linear alkylbenzene sulfonates". Environmental Toxicology and Chemistry. 15 (9): 1638–1648. doi:10.1002/etc.5620150930.

January 01, 1970
alkylbenzene, sulfonate, class, anionic, surfactants, consisting, hydrophilic, sulfonate, head, group, hydrophobic, alkylbenzene, tail, group, along, with, sodium, laureth, sulfate, they, oldest, most, widely, used, synthetic, detergents, found, numerous, pers. Alkylbenzene sulfonates are a class of anionic surfactants consisting of a hydrophilic sulfonate head group and a hydrophobic alkylbenzene tail group Along with sodium laureth sulfate they are one of the oldest and most widely used synthetic detergents and may be found in numerous personal care products soaps shampoos toothpaste etc and household care products laundry detergent dishwashing liquid spray cleaner etc 1 They were introduced in the 1930s in the form of branched alkylbenzene sulfonates BAS However following environmental concerns these were replaced with linear alkylbenzene sulfonates LAS during the 1960s 2 Since then production has increased significantly from about one million tons in 1980 to around 3 5 million tons in 2016 making them most produced anionic surfactant after soaps citation needed The general structure of Sodium dodecylbenzenesulfonates prominent examples of alkylbenzene sulphonates Contents 1 Branched alkylbenzene sulfonates 2 Linear alkylbenzene sulfonates 3 Structure property relationships 4 Environmental fate 5 ReferencesBranched alkylbenzene sulfonates edit nbsp An example of a branched alkylbenzene sulfonate BAS nbsp Extensive foaming Fremont California 1972 Branched alkylbenzene sulfonates BAS were introduced in the early 1930s and saw significant growth from the late 1940s onwards 3 in early literature these synthetic detergents are often abbreviated as syndets They were prepared by the Friedel Crafts alkylation of benzene with propylene tetramer also called tetrapropylene followed by sulfonation Propylene tetramer being a broad term for a mixture of compounds formed by the oligomerization of propene its use gave a mixture of highly branched structures 4 Compared to traditional soaps BAS offered superior tolerance to hard water and better foaming 5 However the highly branched tail made it difficult to biodegrade 6 BAS was widely blamed for the formation of large expanses of stable foam in areas of wastewater discharge such as lakes rivers and coastal areas sea foams as well as foaming problems encountered in sewage treatment 7 and contamination of drinking water 8 As such BAS was phased out of most detergent products during the 1960s being replaced with linear alkylbenzene sulfonates LAS which biodegrade much more rapidly BAS is still important in certain agrochemical and industrial applications where rapid biodegradability is of reduced importance For instance inhibiting asphaltene deposition from crude oil Linear alkylbenzene sulfonates edit nbsp An example of a linear alkylbenzene sulfonate LAS Linear alkylbenzene sulfonates LAS are prepared industrially by the sulfonation of linear alkylbenzenes LABs which can themselves be prepared in several ways 2 In the most common route benzene is alkylated by long chain monoalkenes e g dodecene using hydrogen fluoride as a catalyst 9 The purified dodecylbenzenes and related derivatives are then sulfonated with sulfur trioxide to give the sulfonic acid 10 The sulfonic acid is subsequently neutralized with sodium hydroxide 1 The term linear refers to the starting alkenes rather than the final product perfectly linear addition products are not seen in line with Markovnikov s rule Thus the alkylation of linear alkenes even 1 alkenes such as 1 dodecene gives several isomers of phenyldodecane 11 Structure property relationships editUnder ideal conditions the cleaning power of BAS and LAS is very similar however LAS performs slightly better in normal use conditions due to it being less affected by hard water 12 Within LAS itself the detergency of the various isomers are fairly similar 13 14 however their physical properties Krafft point foaming etc are noticeably different 15 16 In particular the Krafft point of the high 2 phenyl product i e the least branched isomer remains below 0 C up to 25 LAS whereas the low 2 phenyl cloud point is 15 C 17 This behavior is often exploited by producers to create either clear or cloudy products Environmental fate editThe biodegradability of alkylbenzene sulfonates has been well studied 6 18 19 and is affected by isomerization in this case branching The salt of the linear material has an LD50 of 2 3 mg liter for fish about four times more toxic than the branched compound however the linear compound biodegrades far more quickly making it the safer choice over time It is biodegraded rapidly under aerobic conditions with a half life of approximately 1 3 weeks 18 oxidative degradation initiates at the alkyl chain 1 Under anaerobic conditions it degrades very slowly or not at all causing it to exist in high concentrations in sewage sludge but this is not thought to be a cause for concern as it will rapidly degrade once returned to an oxygenated environment References edit a b c Kurt Kosswig Surfactants in Ullmann s Encyclopedia of Industrial Chemistry Wiley VCH 2005 Weinheim doi 10 1002 14356007 a25 747 a b Kocal Joseph A Vora Bipin V Imai Tamotsu November 2001 Production of linear alkylbenzenes Applied Catalysis A General 221 1 2 295 301 doi 10 1016 S0926 860X 01 00808 0 Dee Foster Snell Cornelia T August 1958 50th ANNIVERSARY FEATURE Fifty Years of Detergent Progress Industrial amp Engineering Chemistry 50 8 48A 51A doi 10 1021 ie50584a005 Scheibel Jeffrey J 17 December 2015 The evolution of anionic surfactant technology to meet the requirements of the laundry detergent industry Journal of Surfactants and Detergents 7 4 319 328 doi 10 1007 s11743 004 0317 7 S2CID 93889318 Hill J A 22 October 2008 The Chemistry and Application of Detergents Journal of the Society of Dyers and Colourists 63 10 319 322 doi 10 1111 j 1478 4408 1947 tb02430 x a b Hashim M A Kulandai J Hassan R S 24 April 2007 Biodegradability of branched alkylbenzene sulphonates Journal of Chemical Technology amp Biotechnology 54 3 207 214 doi 10 1002 jctb 280540302 McKinney Ross E 1957 Syndets and Waste Disposal Sewage and Industrial Wastes 29 6 654 666 JSTOR 25033358 Sawyer Clair N Ryckman Devere W 1957 Anionic Synthetic Detergents and Water Supply Problems American Water Works Association 49 4 480 490 Bibcode 1957JAWWA 49d 480S doi 10 1002 j 1551 8833 1957 tb16814 x JSTOR 41254845 Cahn AOCS Ed Arno 2003 5th World Conference on Detergents Reinventing the industry opportunities and challenges Elektronische Ressource ed Champaign Ill AOCS Press ISBN 1 893997 40 5 Roberts David W May 1998 Sulfonation Technology for Anionic Surfactant Manufacture Organic Process Research amp Development 2 3 194 202 doi 10 1021 op9700439 Bipin V Vora Joseph A Kocal Paul T Barger Robert J Schmidt James A Johnson 2003 Alkylation Kirk Othmer Encyclopedia of Chemical Technology doi 10 1002 0471238961 0112112508011313 a01 pub2 ISBN 0471238961 Matheson K Lee August 1985 Detergency performance comparison between LAS and ABS using calcium sulfonate precipitation boundary diagrams Journal of the American Oil Chemists Society 62 8 1269 1274 doi 10 1007 BF02541841 S2CID 98677989 Matheson K Lee Matsoim Ted P September 1983 Effect of carbon chain and phenyl isomer distribution on use properties of linear alkylbenzene sulfonate A comparison of high and low 2 phenyl LAS homologs Journal of the American Oil Chemists Society 60 9 1693 1698 doi 10 1007 BF02662436 S2CID 97659271 Baumgartner F N June 1954 Relation of Molecular Structure to Detergency of Some Alkylbenzene Sulfonates Industrial amp Engineering Chemistry 46 6 1349 1352 doi 10 1021 ie50534a061 Drozd Joseph C Gorman Wilma March 1988 Formulating characteristics of high and low 2 phenyl linear alkylbenzene sulfonates in liquid detergents Journal of the American Oil Chemists Society 65 3 398 404 doi 10 1007 BF02663085 S2CID 93127857 Sweeney W A Olson A C December 1964 Performance of straight chain alkylbenzene sulfonates LAS in heavy duty detergents Journal of the American Oil Chemists Society 41 12 815 822 doi 10 1007 BF02663964 S2CID 98586085 Farn Richard J 2006 Chemistry and technology of surfactants Oxford Blackwell Pub p 96 ISBN 978 14051 2696 0 a b Jensen John February 1999 Fate and effects of linear alkylbenzene sulphonates LAS in the terrestrial environment Science of the Total Environment 226 2 3 93 111 Bibcode 1999ScTEn 226 93J doi 10 1016 S0048 9697 98 00395 7 PMID 10085562 Mackay Donald Di Guardo Antonio Paterson Sally Kicsi Gabriel Cowan Christina E Kane David M September 1996 Assessment of chemical fate in the environment using evaluative regional and local scale models Illustrative application to chlorobenzene and linear alkylbenzene sulfonates Environmental Toxicology and Chemistry 15 9 1638 1648 doi 10 1002 etc 5620150930 Retrieved from https en wikipedia org w index php title Alkylbenzene sulfonate amp oldid 1200908605, wikipedia, wiki, book, books, library,

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