The course of biodegradation of anionic detergents by analyses for carbon,methylene blue active substance and sulfate ion

Tallow alcohol sulfates, ether alcohol sulfates and esters of α-sulfo tallow fatty acids were degraded aerobically by sewage microorganisms in a system in which detergent was the sole source of C. Biodegradation was followed by loss of C and methylene blue active substance (MBAS) and formation of SO ₄ ⁻⁻ . Tallow alcohol sulfates were rapidly and completely degraded; ether alcohol sulfates not quite as readily. Reduction in MBAS was rapid for the α-sulfo esters but loss of C and SO ₄ ⁻⁻ formation was incomplete, possibly because of the intermediate formation of a resistant sulfosuccinate. Sodiump-(1-methylundecyl) benzenesulfonate (LAS) was the reference standard. Presented at the AOCS Meeting, San Francisco, April 1969.     

Soap-based detergent formulations: IX. α-sulfo fatty alkanolamides as lime soap dispersing agents

α-Sulfo fatty alkanolamides were prepared by sodium methylate catalyzed reactions of methyl α-sulfo fatty esters with alkanolamines, such as ethanolamine, N-methyl-2-hydroxyethylamine, diethanolamine, 3-hydroxypropylamine, 2-hydroxypropylamine, and diglycolamine. Pure compounds, such as α-sulfo palmitamides and stearamides, as well as the α-sulfo tallow amides, were prepared and evaluated as surface-active agents. The α-sulfo fatty alkanolamides were found to have excellent stability to alkali. Their stability to acid ranged from excellent in the case of α-sulfo diglycolamides to poor in the case of α-sulfo diethanolamides. Poor stability to acid was related to ease of conversion to ester-amines. Washing tests on standard soil cloths showed that the compounds were good detergents by themselves and were also effective in combination with soap and silicates. Their lime soap dispersant requirements ranged from 7–10. Presented at the AOCS Meeting, September 1973, Chicago. ARS, USDA.     

Soap-based detergent formulations: XV. Amino esters of α-sulfo fatty acids

Amphoteric surfactants were prepared either by direct esterification of α-sulfo fatty acids with various alkanolamines or by rearrangement of the corresponding alkanolamides of the α-sulfo fatty acids to the amino esters with the aid of aqueous hydrochloric acid. The α-sulfo fatty acid monoesters of diethanolamine could be prepared only via the rearrangement method. The amino esters in the C₁₆−C₁₈ range possessed limited water solubility whereas α-sulfolaurate esters were soluble at room temperature. The amino esters were found to be stable to acid hydrolysis; however, they were generally not stable to alkali, by which they were either hydrolyzed or rearranged to the corresponding amide. Only the esters of isopropanolamine and diglycolamine were stable to alkali. Surface active properties of the esters were determined. The lime soap dispersant requirements of the compounds were slightly poorer than those of the corresponding amides. The compounds were good cotton detergents by themselves as well as in combination with soap and a silicate builder. The overall surface active properties of the amino esters were greatly inferior to those of the sulfobetaines previously reported. This indicates that an effective amphoteric lime soap dispersant should have its anionic group located at the very end of the molecule and the cationic group somewhat farther away, instead of the reverse. Presented at the AOCS Meeting, Philadelphia, September 1974.     

The effect of tallow-based detergents on anaerobic digestion

Eight anionic detergents from three general classes (alcohol sulfates,a-sulfo fatty acid esters and alkylbenzenesulfonates were tested for biodegradability under anaerobic conditions of sludge digestion. The alcohol sulfates were found to be readily and completely degraded. Thea-sulfo fatty acid esters did not degrade but had no adverse effect on bacteriological digestion while the alkylbenzenesulfonates used for control purposes did not degrade and disrupted the normal digestion process. Preliminary lysimeter studies showed that sodium isopropyla-sulfostearate is completely degraded, linear alkylbenzenesulfonate 83%, and ABS 35%. Presented at the AOCS meeting, Chicago, 1964. E. Utiliz. Res. Devel. Div., ARS, USDA.     

Alpha sulfo fatty esters in biologically soft detergent formulations

Salts of α-sulfo tallow and coconut esters were subjected to river die-away, activated sludge and Warburg tests, and results show these derivatives to be biologically soft detergents with disappearance curves approximating those of the fatty alcohol sulfates. Selection of the proper fatty acid starting material, alcohol of esterification, and alkali for neutralization provides for a high degree of flexibility in tailor-making biologically soft surface active agents for a wide range of applications. Selected compounds have been found which exhibit remarkable foaming, lime soap dispersing, fabric and hard surface detergency, wetting and related surface-active properties. These properties allow the formulation of a variety of synthetic and soap-synthetic combinations. Primary emphasis is given to the presentation of data on surfactant formulation application studies. Salts of short chain alkyl esters of α-sulfo tallow acid are ideally suited for “combo” soap bar and built heavy-duty detergent applications. Salts of short chain alkyl esters of selected coconut fatty acids are uniquely suitable for light duty liquids, cosmetic and related surfactant applications. An improved process for the manufacture of these sulfo esters has been developed which produces high yield, high purity and light colored products, and which should provide for their acceptance on a large scale in the detergent field. Presented at the 37th Annual AOCS Meeting, Minneapolis, Minn. Oct. 1, 1963.     

Benzyl,cyclohexyl, and phenyl esters ofalpha-sulfo fatty acids

Sodium salts of benzyl, cyclohexyl, and phenyl esters of α-sulfopelargonic, α-sulfopalmitic, and α-sulfostearic acids were prepared by reaction of the α-sulfo acid with excess of the alcohol or phenol, in the presence of methylene chloride, carbon tetrachloride, benzene, or toluene. Synthesis from the acid chloride of the α-sulfo acid gave lower yields of a less pure product. Melting point, surface and interfacial tension, critical micelle concentration, rate of hydrolysis and wetting, foaming and detergent properties were measured. The ring esters have properties similar to the corresponding propyl, butyl, or amyl esters. Presented at the AOCS Meeting, New Orleans, May 1967. E. Util. Res. Dev. Div., ARS, USDA.     

Hexitol and sucrose esters of α-sulfo fatty acids

Use of the α-sulfo acid, the acid chloride and the methyl ester was explored in the preparation of mannitol, sorbitol and sucrose esters of α-sulfopalmitic and α-sulfostearic acids. The products were difficult to purify because of solubilization of reactants. The α-sulfo esters are more soluble and more resistant to hydrolysis than hexitol and sucrose palmitates and stearates. Presented at the AOCS Meeting, New York, October 1968. ARS, USDA.     

Summary of the technology for the manufacture of higher alpha-sulfo fatty acid esters

Interest in α-sulfonated higher molecular weight (up to C₂₀) fatty esters has increased in recent years in the surfactant industry due to the advent of economical sulfonation processes and methyl esters of fatty acids. In this paper, the authors present a review of the chemistry of the sulfonation of fatty esters and the two-step mechanism leading to α-sulfonation. Laboratory and pilot plant scale preparation of long chain fatty acid α-sulfoesters with vaporized SO₃ without the use of solvents are also summarized. Work on the falling film equipment with hydrogenated methyl tallowate with vaporized SO₃ is described along with procedures for neutralization and bleaching. Analytical methods for defining the α-sulfonates are discussed. A larger scale unit to continuously manufacture α-sulfo fatty esters from long chain fatty acid is described. A review of the commercially available continuous processes for sulfonation of the fatty acid esters with vaporized sulfur-trioxide have also been included. The properties of the salts of α-sulfo fatty esters including the hydrolytic stability, aqueous solubility, lime soap dispersing ability, and biological properties have been tabulated. Uses of these surfactant range α-sulfo esters are included in this discussion. Presented at the AOCS Meeting, New Orleans, April 1976.     

Long chain alkanesulfonates and 1-hydroxy-2-alkanesulfonates: Structure and property relations

Even chain sodium alkanesulfonates from the Strecker reaction, odd chain sodium alkanesulfonates from the alkaline decarboxylation of α-sulfo acids, and sodium 1-hydroxy-2-alkanesulfonates from the reduction of esters of α-sulfo acids were compared with respect to Krafft point, critical micelle concentration, detergency and foam height. Sodium alkanesulfonates and crude fusion products from the α-sulfo acids (mixtures of alkanesulfonates of one less carbon atom with a lesser amount of a soap of two less carbon atoms) are more soluble and have better detergent and foaming properties. Sodium 1-hydroxy-2-alkanesulfonates resemble monosodium salts of α-sulfo acids. Alkanesulfonic acids and 1-hydroxy-2-alkane-sulfonic acids obtained from the sodium salts by ion exchange have lower Krafft points and are more readily soluble. The critical micelle concentrations of 1-hydroxy-2-alkanesulfonic acids and α-sulfo acids are nearly the same and about equal to those of alkanesulfonic acids of one less carbon atom. Presented at the AOCS meeting in Toronto, Canada, 1962. A laboratory of the E. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Soap-based detergent formulations I. Comparison of soap-lime soap dispersing agent formulations with phosphate built detergents

Blends of soap with small amounts of lime soap dispersing agents are efficient detergents in hard water and require little or no tripolyphosphate builder. Lime soap dispersing agents examined include sulfated ethoxylated fatty alcohols, sulfated N-(2-hydroxyethyl) fatty amides, methyl esters of α-sulfo fatty acids, 2-sulfoethyl fatty acid esters and N-methyl-N-(2-sulfoethyl) fatty amides as well as nonionics derived from tallow alcohols. Detergency evaluations were carried out with three commercial soiled cotton cloths as well as by a laboratory multi-wash technique. Formulations containing 80% soap, 10% lime soap dispersing agent and 10% builder gave optimum detergency values. Builder effectiveness was rated tripolyphosphate>silicate (1:1.6)> metasilicate = citrate = oxydiacetate = nitrilotriacetate>carbonate≫sulfate. The detergency of soap-lime soap dispersed combinations compared favorably with a standard brand household heavy duty granular detergent in 50, 150 and 300 ppm hardness water on three soiled cloths. Presented at the AOCS Meeting, Atlantic City, October 1971. East. Market. Nutr. Res. Div., ARS, USDA.     

Ether alcohol sulfates from oleyl alcohol

Oleyl alcohol was caused to react with ethylene oxide, propylene oxide, and 1,2-butylene oxide in the presence of an alkaline catalyst. The first and second derivatives from each reaction were isolated by fractional distillation. Sulfation with dioxane-SO₃ gave high-purity oleyl ether sulfates, easily soluble, with good detergent and lime soap-dispersing properties. The use of chlorosulfonic acid or sulfuric acid as the sulfating agent for oleyl ether alcohols resulted in about 60% retention of the double bond, compared with oleyl alcohol, which under the same conditions retained only about 25% unsaturation. Oleyl ether alcohols sulfated with chlorosulfuric acid or sulfuric acid are easily sobuble and have good lime soap-dispersing properties. They are able to solubilize less soluble soaps and saturated ether alcohol sulfates. Presented at the AOCS Meeting, New Orleans, May 1967 E. Utiliz. Res. Dev. Div., ARS, USDA     

Sodium alkyl α-sulfopelargonates,C7H15CH(SO3Na)CO2R. Wetting and related properties

A series of sodium alkyl α-sulfopelargonates prepared from sodium α-sulfopelargonic acid and alcohols of from 2 to 12 carbon atoms were examined for surface active properties. Esters with the hydrophilic portion in the middle of the molecule, as in sodium hexyl, heptyl octyl, capryl (or 2-octyl) and 2-ethylhexyl α-sulfopelargonate were very efficient wetting agents with good foaming properties and a c.m.c. of from 2 to 7 millimoles per liter. The presence of the α-sulfo group inhibits hydrolysis of the ester linkage, apparently by steric hindrance. Sodium capryl α-sulfopelargonate, an ester of a secondary alcohol, was particularly stable to acid and alkaline hydrolysis. The esters are easily soluble in water, organic solvents and mineral oil. Presented at the annual meeting, American Oil Chemists' Society, St. Louis, Missouri, May 1–3, 1961. Eastern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Polyhydric alcohol esters of α-sulfo fatty acids

Direct esterification of α-sulfopalmitic and α-sulfostearic acids with excess ethylene glycol, glycerol, pentaerythritol and 2-methoxyethanol was carried out in carbon tetrachloride to give products containing essentially monoesters. Surface active properties of these compounds were measured with emphasis on washing ability in combination with soap. The detergency of these esters was compared with those of hexitol and sucrose α-sulfo fatty acid esters. Although the esters had moderate lime soap dispersing ability, their detergency showed synergism when combined with soap. Deceased. East. Market. Nutr. Res. Div., ARS, USDA.     

Synthetic detergents from animal fats. V. Esters from alpha-sulfonated fatty acids and sodium isethionate

Summary Disodium 2-sulfoethyl α-sulfopalmitate, disodium 2-sulfoethyl α-sulfostearate, and disodium 2-sulfoethyl α-sulfobehenate were prepared by esterification of the corresponding α-sulfonated acid with sodium isethionate. Disodium 1-methyl-2-sulfoethyl α-sulfostearate was made from sodium 2-hydroxypropanesulfonate. The esters were found to be readily soluble surface-active agents and detergents, very responsive to building with inorganic phosphates and sulfates. Compared to sodium 2-sulfoethyl oleate the esters were readily prepared without the necessity of making the acid chloride; they were considerably more resistant to acid or alkaline hydrolysis; they were about equal in their excellent lime soap dispersing power, but inferior in foaming properties, producing a less permanent foam. The esters were easily soluble because of the presence of two sulfo groups and were improved detergents in the presence of inorganic builders. Mixtures of the palmitic and stearic acid derivatives, such as might be obtained from the saturated acids of tallow, containing a total of 20% active ingredient, were effective detergents in hard water. Disodium 1-methyl-2-sulfoethyl α-sulfostearate, an ester of a secondary alcohol, was even more resistant to alkaline hydrolysis than the esters from sodium isethionate. Presented at the meeting of the American Oil Chemists’ Society, New Orleans, April, 1955. A laboratory of the Eastern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.     

The workhorse surfactants: LAS,alcohol sulfates,and ether sulfates

Relative market volumes are discussed illustrating why LAS, alcohol sulfates, alcohol ether sulfates, and branched chain alkylene benzene sulfonates are called “workhorse” surfactants. Typical heavy duty powder, heavy duty liquid, and light duty liquid formulations from around the world are given for each material. Low mole ether sulfates for heavy duty powders are discussed as to chemical constituency and performance. Comparisions of LAS to paraffin sulfonates and olefin sulfonates are given for light duty liquid formulations. Shampoo performance advantages of alcohol sulfates over olefin sulfates are illustrated.     

Alcohol ether sulfates in shampoos

Mono-, di- and triethanolamine sulfates of several different molecular weight alcohol ether sulfates were formulated into shampoos. The ethylene oxide content of the alcohol ethoxylates varied from about 20 to 60%, although 40% was usual. The shampoo formulation was 20% active ether sulfate and 5% foam stabilizer. Lauric diethanolamide and amine oxides were used as foam stabilizers. The shampoos were tested for quality and quantity of foam, viscosity and cloud point. Although no “hair effects” tests were run, a limited home use test was made. Alcohol ether sulfate shampoos are equal or superior to several popular commercial products on the basis of a laboratory foam test. They are comparable in foam to alcohol sulfates in similar formulations. Cloud points of these shampoos were generally good. Amine oxide foam stabilizers reduced the cloud point more than the amide. Viscosities of the shampoos were readily controllable. Although the choice of alkanolamine, alcohol molecular weight and degree of ethoxylation had some effect on these properties, none were highly critical; this allows considerable leeway in their selection. The home use tests assured us that these shampoos were not obviously deficient in the desired “hair effect” properties. The literature records that alcohol ether sulfates are preferred to alcohol sulfates for low skin and eye irritation. By varying the free oil (unsulfated ethoxylate) content and making the proper choice of ether sulfate and foam stabilizer, bright and clear liquid shampoos with viscosities from about 10 centipoise to over 50,000 centipoise were made. The latter are essentially gels. Paste shampoos were also made from these ether sulfates. Presented at the AOCS Meeting, Chicago, October 1967. Now with Stepan Chemical Company, Northfield, Illinois.     

Thermal rearrangement of sulfated tallow alkanolamides

A study of reaction variables in the sulfation of tallow alkanolamides revealed that a molecular rearrangement to aminoester occurs as a result of prolonged heating in the unneutralized state. Heating sulfated isopropanolamide for 4 hr at 60 C resulted in a 60% loss of active ingredient. The sulfated diglycolamide heated at 60 C for 12 hr suffered a loss of 22% active ingredient. A 50:50 mixture of these sulfated alkanolamides heated for 12 hr at 40 C incurred no loss of active ingredient content, whereas at 60 C a 40% loss of active ingredient was observed. Thus, careful temperature control and rapid neutralization after sulfation are required to obtain sulfated alkanolamides with a high percentage of active ingredient. Agricultural Research, Science and Education Administration, USDA.     

Soap and related products: Palm and lauric oil

There are three main methods for producing soap: direct saponification of fats and oils, neutralization of fatty acids and saponification of fatty acid methyl esters. Our unique process of soapmaking, based on the methyl ester saponification method, is described here. By this process, high-quality toilet soaps can be produced from palm stearin and palm kernel oil as well as tallow and coconut oil. A new sulfonation process was developed to produce high-quality α-SFMe (α-sulfo fatty acid methyl ester) from palm stearin as the starting material. Quality and performance of α-SFMe bear comparison with those of LAS, AES, AS or AOS. Thus α-SFMe is a promising surfactant for detergents and will contribute to expanding the use of palm oil in the near future.     

Biological behavior of some soap-based detergents

The biodegradability of tallow soap, three soap-based detergent formulations and their component lime soap dispersing agents—sodium methyl α-sulfotallowate, sulfated N-(2-hydroxypropyl) tallowamide, and sodium N-methyl N-(2-sulfoethyl) tallowamide—was determined under aerobic and microaerophilic conditions. Both sewage and river water microorganisms were used as the sources of inoculum. The course of biodegradation was followed by loss of carbon and methylene blue active substance, and by increase in turbidity and surface tension. Carbon analysis for soap in solutions containing Ca⁺⁺ and Mg⁺⁺, which would precipitate soap, was performed by an improved technique using the disodium salt of ethylenediamine tetraacetic acid. Invariably a decrease in carbon content was accompanied by an increase in turbidity and surface tension. Also, loss in methylene blue active substance was concurrent with an increase in turbidity and surface tension of the degrading solutions of the detergent. Soap cannot be determined as methylene blue active substance because of the low pH of the test. Soap and the built soap formulations degraded under aerobic and microaerophilic conditions. Preliminary toxicity data upon mammals and fish indicated that the soap-based detergents are as safe as conventional commercial detergents. ARS, USDA.     

Darstellung und Eigenschaften von Fettsäurepolyglykolestersulfaten

Production and Properties of Fatty Acid Polyglycol Ester Sulfates Fatty alcohol oxethylates, produced by reaction of fatty alcohols from hydrogenated fatty acid methyl esters with ethylene oxide, are the basic material for an important class of anionic tensides, the fatty alcohol ether sulfates. The fatty acid polyglycol ester sulfates are a very interesting alternative to the fatty alcohol ether sulfates. The former are available by saving hydrogenation, in principle directly by fatty acid oxethylation or interesterification of fatty acids with polyglycols, followed by sulfatation. We report about the production of fatty acid ester sulfates by sulfatation of the fatty acid polyglycol monoesters by sulfurtrioxide or chlorosulfonic acid. By means of the results of physicochemical measurements and process trials it is discussed how far fatty acid polyglycol monoester sulfates are suited as alternative tenside raw material fatty alcohol ether sulfates.