Hydroxyalkane sulfonate

A.lpha-Olefm Sulfonates. Sulfonation of alpha-olefins yields a mixture of alkene sulfonates, hydroxyalkane sulfonates, and some amount of various disulfonates. These detergents are excellent foamers with good detergency properties. They are unaffected ia hard water and thek effects are considered superior to the alkyl ether sulfates (9). 

The direct reaction of 1-alkenes with strong sulfonating agents leads to surface-active anionic mixtures containing both alkenesulfonates and hydroxyalkane sulfonates as major products, together with small amounts of disulfonate components, unreacted material, and miscellaneous minor products (alkanes, branched or internal alkenes, secondary alcohols, sulfonate esters, and sultones). Collectively this final process mixture is called a-olefinsulfonate (AOS). The relative proportions of these components are known to be an important determinant of the physical and chemical properties of the surfactant [2]. 

Replacing a hydrogen atom in any of the methylene groups by a hydroxide function significantly reduces the retention time. The position of the hydroxide function exerts a noticeable influence on the resulting retention time. Fig. 5-35 shows the separation of two Ci6-hydroxyalkane sulfonates, which are hydroxy-substituted in the 2- and 3-pos-ition of the alkyl chain. In comparison to non-substituted alkane sulfonates, the retention decrease corresponds to the loss of 2 to 3 methylene groups from the solvophobic alkyl groups. 

Fig. 5-35. Separation of two hydroxyalkane sulfonates with different hydroxide group position. — Separator column IonPac NS1 (10 pm) eluent 0.01 mol/L NH4OH / acetonitrile (62 38 v/v) flow rate 1 mL/min detection suppressed conductivity injection volume 50 pL solute concentrations 100 ppm each of C 14-alkane sulfonate (2-hydroxy) (1), C16-alkane sulfonate (3-hydroxy) (2), and C16-alkane sulfonate (2-hydroxy) (3).

CAS 68439-57-6 EINECS/ELINCS 270-407-8 Synonyms Sodium oc-olefin (C14-C16) sulfonate Definition Mixt. of long chain sulfonate salts from sulfonation of Cl 4-16 alpha olefins consists of sodium alkene sulfonates and sodium hydroxyalkane sulfonates Properties Anionic Toxicology TSCA listed... 

In all the eases, the first step of the reaetion leads to the formation of eyelie intermediates (P-sultones), whieh rapidly undergo isomerization to unsaturated sulfonie aeids and (in the ease of linear and internal, but not vinylidene olefins) the more stable y- and 8-sultones. These sultones ean be hydrolyzed to hydroxyalkane sulfonates. 

Another class of sulfonates is the a-olefin sulfonates which are prepared by reacting linear a-olefin with sulfur trioxide, typically yielding a mixture of alkene sulfonates (60-70%), 3- and 4-hydroxyalkane sulfonates ( 30%) and some disulfonates and other species. The two main a-olefin fractions used as starting material are C12-C16 and Cig-Cig. 

The major sulfonation process uses sulfur trioxide as the reactant and yields alkene sulfonic acids as preliminary products, together with various sultones (mainly 1,3 and 1,4 sultones corresponding to the more probable positions of the intermediate carbonium ion in the successive molecular rearrangements). Further alkaline hydrolysis of sultones yields hydroxyalkane sulfonates and alkene sulfonates (illustrated belo for 1,3 alkane sultone). An acidic hydrolysis of sultones produces alkene sulfonates as major products. 

The content of sulfatosulfonates can be estimated by measuring the active agent content by titration with benzethonium chloride before and after acid hydrolysis. Hydrolysis converts the sulfatosulfonates to hydroxyalkane sulfonates, which add to the assay value (81). 

Methyl esters are prepared by reaction with diazomethane, dissolved in petroleum ether and added to the column. Hydrocarbons are eluted with 150-200 mL petroleum ether. Alkenesulfonates are eluted with 500 mL 90 10 petroleum ether/ ethyl ether and hydroxyalkane sulfonate and all disulfonates are eluted with 500 mL ethyl ether. Unesterified material is removed with 50 50 ethyl ether/MeOH. 

Elute with 30 70 2-propanol/0.5 M NaCI solution, monitoring the separation by spectrophotometry with methylene blue method. Hydroxyalkane sulfonates elute first, followed by alkene... 

Elute with 30 70 2-propanol/0.2 M NaCl solution, monitoring the effluent by two-phase titration using bromcresol green indicator. Order of elution (1) toluenesulfonic acid (2) the group of alkylsulfate, alkylsulfonate, hydroxyalkane sulfonate, and sulfosuccinate (3) the group of ABS, alkenesulfonate, and higher MW alkylsulfonate (4) soap. 

The components of a-olefin sulfonates, namely alkenesulfonates, hydroxyalkane sulfonates, and the corresponding disulfonates, can be determined by TLC on Silica Gel G, with development with chloroform/methanol/sulfuric acid and visualization by sulfuric acid charring or other means (25,26). Rf values increase in the order disulfonates, hydroxyalkane monosulfonates, alkenesulfonates, and unsulfonated oil, with no differentiation by alkyl chain length (see Table 5). 

Collisionally activated dissociation. Hydroxyalkane sulfonates cannot be differentiated from alkyl sulfates by simple electrospray MS in negative ion mode because the parent ions are similar. However, CAD shows a daughter ion at m/z 80, indicating a sulfonate, and neutral loss of a water, characteristic of the hydroxyalkane compound (15). 

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