Alkylbenzenes, alkylation sulfonation

The major uses of linear alkylbenzenes are in the manufacture of linear alkyl sulfonates, LAS, for laundry (70%), light duty dishwashing liquids (15%), industrial cleaners (12%), and household cleaners (3%). 

A wide use of synthetic detergents (SD) began in the forties of the 20" century, after mastering the commercial production of anionics (alkyl sulfonates - Germany alkylbenzene sulfonates -USA, United Kingdom) and nonionics (ethoxylated alkyl benzenes - Germany). 

Anionic surfactant Alkylbenzene sulfonate, paraffin sulfonate, olefin sulfonate, secondary alkane sulfonate, alkyl sulfonate, dialkyldiphenylether disulfonate 0-3... 

Yet, the reality is complex and sometimes ambiguous. For example, at a certain low level of residual ionic calcium, around 0.5 mmol of calcimn per liter, the detergent effect of such anionic surfactants as sodium alkylbenzene sulfonate is enhanced [4,5]. Several explanations have been suggested for his phenomenon, but, so far, it has been impossible to settle the question. It is certain that divalent cations help increase the size of the micelles of anionic surfactants, which may improve cleaning power. Calcium in very substoichio-metric amoimts with respect to an alkyl sulfonate will cause no precipitation but will rather lower the critical micelle concentration or possibly the existence of surfactant units with two hydrophobic heads. Finally, free calcium may increase the adsorption of anionic surfactants on textiles like cotton, and such adsorption as the fiber-water interfaces is well known as a mechanism that explains soil removal. 

Sodium alkane (C14-C18) sulfonate. See Sodium C14-18 alkane sulfonate Sodium alkane sulfonate. See Sodium alkyl sulfonate Sodium alkylbenzene sulfonate, branched. See Sodium dodecylbenzene-sulfonate... 

The second source of sulfonic acid uses the following reaction scheme alkylation of benzene by a propylene oligomer then sulfonation of the alkylbenzene. 

Alkylation of benzene using alpha olefins produces linear alkylbenzenes, which are further sulfonated and neutralized to linear alkylbenzene sulfonates (LABS). These compounds constitute, with alcohol ethoxy-sulfates and ethoxylates, the basic active ingredients for household detergents. Production of LABS is discussed in Chapter 10. 

Typical properties of detergent alkylate are shown in Table 10-2. Detergent manufacturers buy linear alkylbenzene, sulfonate it with SO3, and then neutralize it with NaOH to produce linear alkylbenzene sulfonate (LABS), the active ingredient in detergents ... 

As esters of sulfuric acid, the hydrophilic group of alcohol sulfates and alcohol ether sulfates is the sulfate ion, which is linked to the hydrophobic tail through a C-O-S bond. This bond gives the molecule a relative instability as this linkage is prone to hydrolysis in acidic media. This establishes a basic difference from other key anionic surfactants such as alkyl and alkylbenzene-sulfonates, which have a C-S bond, completely stable in all normal conditions of use. The chemical structure of these sulfate molecules partially limits their conditions of use and their application areas but nevertheless they are found undoubtedly in the widest range of application types among anionic surfactants. 

The CMC of commercial AOS and other surfactants at 40°C has been determined by Gafa and Lattanzi [6] who plotted the surface tension of aqueous surfactant solutions against concentration. The surface tensions were determined with the ring method according to du Nouy. Table 5 gives their CMC values in mmol/L and the surface tension at the CMC in mN/m. Table 5 also contains CMC values of isomerically pure sodium alkyl sulfates, sodium alkylbenzene-sulfonates, sodium hydroxyalkanesulfonate, and sodium alkenesulfonates at 40°C, taken from the literature [39 and references cited therein]. 

The thermal degradation of alkylbenzene sulfonates in alkaline media is important because of the application at elevated temperatures. The half-lives, with respect to thermal degradation, of several commercially available sulfonates were estimated at hundreds to thousands of years at 204° C. The degradation mechanism was predominately a clipping of the alkyl chain to yield an alkylbenzene sulfonate with the phenyl group attached to the a-carbon however, desulfonation also occurred [1624]. 

Alkylbenzene sulfonic acid, quahty optimization of, 23 552 Alkyl (C12-C15) benzoate, 3 635 Alkylbenzyldimethylammonium chlorides, 2 21... 

Commercial linear alkylbenzene sulfonates (LAS) contain mixtures of several alkyl chain homologues each with a variable number of... 

A broad range of information pertaining to the toxicity of several classes of surfactants including anionic (linear alkylbenzene sulfonates (LAS), alkylether sulfates (AES), alkyl sulfates (AS), non-ionic (alkylphenol ethoxylates (APEO)), cationic (ditallow dimethyl ammonium chloride (DTDMAC)—a group of quaternary ammonium salts of distearyl ammonium chloride (DSDMAC)) and amphoteric surfactants (alkyl-betaines) is available. Several reviews of the scientific literature have been published [3-5,20]. 

Linear alkylbenzene sulfonate (LAS) and the sodium salt Na-LAS (P550), alkyl sulfate (AS) Ci2-Ci4, alkylether sulfate (AES), alcohol ethoxylate (AE) 1012/60, methylester sulfonate (MES) Ci6-Ci8, Na-lauryl sulfate, 1-octane sulfate Na, 1-decan sulfonate Na, 1-hexadecan sulfonate Na, Laurie alcohol, 1-octanol (A. Caprilico), 1-nonanol, n-decyl-alcohol, 1-undecanol, 1-tridecanol, miristic alcohol (1-tetradecanol), 1-pentadecanol, cetyl-alcohol (1-hexadecanol), 1-hep-tadecanol, estearil alcohol (1-octadecanol), nonadecanol, araquidil alcohol (1-ecosanol), heneicosanol, behenil alcohol (1-docosanol),... 

ABS AE AE/P AES AG AOS APEO APG AS BiAS BM c6(EO)3 CNPEC CTAS D DATS DCPEG DEEDMAC branched alkylbenzene sulfonate alcohol ethoxylate alcohol ethoxylate/propoxylate alkylether sulfate alkyl glucamide a-olefin sulfonate alkylphenol ethoxylate alkyl polyglucoside alkyl sulfate bismuth active substances alkyldimethylbenzyl ammonium triethylene glycol monohexyl ether carboxylated nonylphenoxy carboxylates cobalt thiocyanate active substances R2S10(o.5)2 dialkyl tetralinsulfonate dicarboxylated PEG ditallow ester of di(hydroxyethyl)dimethyl ammonium chloride... 

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