Sulfur-containing surfactants

Sulfation and Sulfonation. a-Olefin reactions involving the introduction of sulfur-containing functional groups have commercial importance. As with many derivatives of olefins, several of these products have appHcations in the area of surfactants (qv) and detergents. Typical sulfur reagents utilized in these processes include sulfuric acid, oleum, chlorosulfonic acid, sulfur trioxide, and sodium bisulfite. 

One of the longest known synthetically prepared surfactants are the fatty alcohol sulfates, which were prepared on technical scale before 1940. Along with their ethoxylated counterparts, the fatty alcohol ether sulfates, which appeared on the stage shortly after, their use in toiletries is very popular but they can also be found in products for textile industry and auxiliaries in emulsion polymerization. With the exception of soaps, the mentioned anionic surfactants all have a sulfur-containing functional group. Denying the differences between these, their skin irritancy potential is remarkably high. 

Sulfonates, aliphatic la 388, 389 Sulfones lb 321,360 Sulfonic acids la 91 Sulfonylurea derivatives lb 204 Sulfoxides lb 321,358,360,372,373,374 Sulfur compounds lb 338 Sulfur-containing compounds lb 301,339 Sulfur dioxide vapor la 86 -, dipole moment la 97 Sulfur, divalent lb 302 Sulfuric acid la 87,195,333,411,426 Sulfur ions lb 302 Sulfutyl chloride vapor la 86 Sulpyrid lb 268 Sunflower seed oil lb 286 Surfactant-TLC plates la 89 Sweeteners la 44, 388-390 Swep la 108... 

The polysulfide and elemental sulfur were unstable to autoclaving. This fact necessitated the use of a membrane to achieve sterility in those cases. The surfactant not only provided greater surface area but also minimized the amount of sulfide in contact with atmospheric oxygen since the sulfide was generally dispersed throughout the medium. The fate of the non-sulfur-containing hydrocarbons, while of real interest, is beyond the scope of this present work. 

Sorbic acid is incompatible with bases, oxidizing agents, and reducing agents. Some loss of antimicrobial activity occurs in the presence of nonionic surfactants and plastics. Oxidation is catalyzed by heavy-metal salts. Sorbic acid will also react with sulfur-containing amino acids, although this can be prevented... 

The chemical and physical evidence presented here shows that aquatic foams collected from pristine environments may have an entirely natural origin. The carboxyl moiety is the dominant anion of the surfactant as foaming ability and stability change dramatically over the pKa range of the carboxyl group (pH 3-5) (25). Most commercial anionic surfactants contain sulfur-containing anions which are not... 

FIGURE 7.1 Sulfonation and sulfation agents for the manufacture of sulfur-containing anionic surfactants. (After Falbe, J., ed., Surfactants in Consumer Products Theory, Technology and Application, Springer, Berlin, 1986. With permission.)... 

To overcome these difficulties, drilling fluids are treated with a variety of mud lubricants available from various suppHers. They are mostly general-purpose, low toxicity, nonfluorescent types that are blends of several anionic or nonionic surfactants and products such as glycols and glycerols, fatty acid esters, synthetic hydrocarbons, and vegetable oil derivatives. Extreme pressure lubricants containing sulfurized or sulfonated derivatives of natural fatty acid products or petroleum-base hydrocarbons can be quite toxic to marine life and are rarely used for environmental reasons. Diesel and mineral oils were once used as lubricants at levels of 3 to 10 vol % but this practice has been curtailed significantly for environmental reasons. 

Gas turbine fuels can contain natural surfactants if the cmde fraction is high in organic acids, eg, naphthenic (cycloparaffinic) acids of 200—400 mol wt. These acids readily form salts that are water-soluble and surface-active. Older treating processes for sulfur removal can leave sulfonate residues which are even more powerful surfactants. Refineries have installed processes for surfactant removal. Clay beds to adsorb these trace materials are widely used, and salt towers to reduce water levels also remove water-soluble surfactants. In the field, clay filters designed as cartridges mounted in vertical vessels are also used extensively to remove surfactants picked up in fuel pipelines, in contaminated tankers, or in barges. 

Acid dyes used for coloring animal fibers via acidified solution (containing sulfuric acid, acetic acid, sodium sulfate, and surfactants) in combination with amphoteric protein. 

Fuming sulfuric acid containing 10-60% sulfur trioxide hydrolyzes perfluoro-Af-alkylcyelic amines to perfluoro-Al-alkyl lactams. Mercuric sulfate acts as a Catalyst [JO, 31] (equation 33). The lactams ate highly reactive and can be used to prepare polymenc films and surfactants... 

Surfactants are prepared which contain carboxylic acid ester or amide chains and terminal acid groups selected from phosphoric acid, carboxymethyl, sulfuric acid, sulfonic acid, and phosphonic acid. These surfactants can be obtained by reaction of phosphoric acid or phosphorus pentoxide with polyhydroxystearic acid or polycaprolactone at 180-190°C under an inert gas. They are useful as polymerization catalysts and as dispersing agents for fuel, diesel, and paraffin oils [69]. 

Modem commercial detergents are mixtures. Their most important component is a surfactant, or surface-active agent, which takes the place of the soap. Surfactant molecules are organic compounds with a structure and action similar to those of soap. A difference is that they typically contain sulfur atoms in their polar groups (4). 

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