Physical properties of blends of soap and lime soap dispersants

The mechanism of action of soap lime-soap dispersant (LSDA) combinations is based on a close association between these two components. In deionized water this association is mixed micellar. Surface tension curves confirm the presence of mixed micelles in deionized water and show a combination of optimum surface active properties (low critical micelle concentrations (CMC), high surface concentration and low surface tension above the CMC). Solubilization of high Krafft point soap by LSDA and of difficultly soluble LSDA by soap are related results of this association. Analysis of dispersions of mixtures of soap and LSDA in hard water shows that the dispersed particles are mixtures of soap and LSDA in the same proportion as they were originally added. These findings are inconsistent with the view that soap reacts separately with hard water ions and that the resulting lime soap is suspended by surface adsorption of LSDA. The suspended particles are responsible for surface active properties and detergency and do not permit deposits on the fabric like those found with soap alone.     

Soap-based detergent formulations: XII. Alternate syntheses of surface active sulfobetaines

Sulfopropylated amphoteric surfactants, previously reported in this journal, displayed excellent surface active properties and were good detergents in combination with soap. New synthetic routes were investigated for the preparation of such types of compounds to provide a more economical process and eliminate the hazards due to propanesultone, which was used in the previously reported synthetic procedure. A series of 2-hydroxy-3-sulfopropyl amphoteric surfactants was prepared by reacting sodium 3-chloro-2-hydroxy-1-propanesulfonate (the addition product of sodium bisulfite to epichlorophydrin) with various primary fatty amines as well as with fat derived N,N-dimethylalkylamines. Quaternary sulfobetaines not possessing a hydroxyl group were obtained from tertiary amines by reaction with allyl chloride followed by bisulfite addition. The solubility behavior (Krafft points) of these compounds indicated that they were not identical with the sulfobetaines prepared with the aid of propanesultone. The secondary and quaternary ammonium compounds exhibited limited water solubility but were good lime soap dispersing agents. They displayed good detergency in combination with soap. The quaternary ammonium derivatives were particularly effective on cottonpolyester blend fabrics. Presented at the AOCS Meeting, Philadelphia, September 1974.     

Surface active properties of combinations of soap and lime soap dispersing agents

Surface tension versus log concentration curves were obtained for combinations of a variety of lime soap dispersing agents (LSDA) with sodium oleate. Salient features of the curves for these mixtures were: (a) criticial micelle concentration (CMC) close to that for LSDA alone; (b) absence of a surface tension minimum or substantial reduction in the minimum, which was often found with LSDA alone; (c) surface tension values above the CMC very close to those found for soap alone above its CMC; and (d) slope below the CMC greater than that for soap alone, more like that for soap with alkali added or lime soap dispersing agent alone. Higher CMC values were confirmed by dye solubilization measurements. The surface tension curves provided further evidence for the mixed micellar nature of soap-LSDA mixtures and suggested that the addition of LSDA to soap increased the surface concentration of surfactant. Presented at the AOCS Meeting, Chicago, September 1976.     

Soap-based detergent formulations: XXVI. Hard water detergency of soap-lime soap dispersant combinations with builders and inorganic salts1

Blends of soap and 3 lime soap dispersants—the sulfated tallow alkanolamide (TAM), the coconut-oil-derived amido sulfobetaine (CAHSB) and the cocoamido betaine (CAB)—were formulated with 3 builders—sodium tripolyphosphate (STPP), trisodium nitrilotriacetate (NTA) and trisodium 2-oxa-1,1,3-propane tricarboxylate (OPT). Varying amounts of sodium sulfate were added to these formulations, and the effects of builders and sodium sulfate on detergency at 300 ppm water hardness were studied. At levels below 60%, STPP was not an effective builder for TAM formulations. Dilution of STPP-built TAM formulations with sodium sulfate substantially decreased detergency. Detergency of TAM formulations was improved by incorporation of NTA or OPT and such formulations could tolerate dilution with sodium sulfate without serious loss in detergency. NTA or STPP improved the detergency of CAB formulations but OPT did not. Addition of sodium sulfate caused some loss in detergency in all CAB formulations. Addition of STPP to CAHSB formulations caused a slight loss in detergency, but addition of NTA or OPT had no appreciable effect. Dilution of STPP-built CAHSB formulations with sodium sulfate affected detergency adversely, although not as severely as in STPP-built TAM formulations. Dilution of NTA-or OPT-built CAHSB formulations with sodium sulfate had little effect on detergency. CAB and particularly CAHSB are superior to TAM in dispersing lime soap curd. Therefore, addition of NTA, STPP, or OPT to the amphoteric formulations did not affect detergency to the same extent as in TAM formulations. Further evidence of the superiority of amphoteric lime soap dispersing agents (lsda) in dispersing lime soap curd was provided by the effectiveness of soap, CAHSB, silicate formulations in detergency studies at 1,000 ppm water hardness. Presented at the Annual AOCS Meeting, San Francisco, April 1979. Agricultural Research, Science and Education Administration, U.S. Department of Agriculture.     

New amphoteric surfactants containing a 2-hydroxyalkyl group: IV. Performance of amphoteric surfactant/soap blends

The performance of new amphoteric surfactants,N-(2-hydroxyethyl)-N-(2-hydroxyalkyl)-β-alanines (HAA) and their oxyethylated derivatives (HAA-nEO) was studied in blends with a fatty acid soap. The solubility, foaming power and fabric detergency were measured for blends of (Na-HAA or Na-HAA-nEO)/soap. Furthermore, lime soap dispersing power, toxicity to fish and biodegradability for HAA or HAA-nEO homologs were examined and evaluated. The blend of tallow soap and not less than 10% of C_12–14-Na-HAA exhibited better solubility behavior than tallow soap or tallow/coconut oil soap alone. Fabric detergency was improved by blending Na-HAA with soap. Soil deposition in Na-HAA/soap or Na-HAA/soap/Na₂CO₃ solution was measured. On the basis of the results for: (a) the measurements of redeposition; (b) interfacial tension between oil and water and (c) contact angle between oil and fabric in water, it was presumed that since Na-HAA adsorbed more or less in preference to soap on the surface of fabric in water, soil redeposition would be prevented in the Na-HAA/soap detergent solution.     

Soap and lime soap dispersants

In recent decades, soap has largely been replaced by petrochemicals and polyphosphates as the major components of laundry detergents in the U.S. Currently, the use of soap is primarily confined to the toilet soap bar field, and technological advances here have been mainly in processing. In view of the rising costs and increasing scarcity of petrochemicals and polyphosphates, tallow, a replenishable, inexpensive agricultural by-product, was examined as an alternate raw material. Tallow soap has a long history of efficacy and safety but suffers from poor performance in hard water and insolubility in cold water. It has now been shown that the performance of soaps can be drastically improved in cold water solubility and in hard water detergency by the addition to the soap of lime soap dispersing agents (LSD A). These are anionic or amphoteric surfactants possessing one or more bulky polar groups. These soap-LSDA combinations form mixed micelles in water and essentially take on the surface active characteristics of a single anionic surfactant. Soap-LSDA combinations wash well in hard water without curd formation; they can be “built” with various materials such as phosphates and trisodium nitrilotriacetate (NTA) to enhance detergency. Soap-LSDA combinations equal the conventional detergents in every performance respect and undergo biodegradation more readily and completely.     

9,10,12,13-四羟基硬脂酸钠在低温硬质水及中性pH条件下的特异性能

以天然亚油酸为原料,经氧化水解制备得到9,10,12,13-四羟基硬脂酸(THSA),采用FTIR、ESI-MS和1HNMR表征了THSA的结构。测定了THSA的钠皂9,10,12,13-四羟基硬脂酸钠(STHS)的克拉夫特点、钙离子稳定性、钙皂分散剂消耗量、表面张力、临界胶束浓度和泡沫性能,并与对照物亚油酸、油酸及硬脂酸的钠皂进行比较。结果表明,STHS具有其他脂肪酸钠皂不具备的优秀钙皂分散性能和钙离子稳定性,并在低温和中性条件下显示出更好的水溶性。STHS不仅克服了普通脂肪酸钠皂不耐硬水和中性条件下溶解性差两大共同缺陷,也克服了饱和脂肪酸钠皂低温溶解性差以及不饱和脂肪酸钠皂易氧化酸败的缺点,因此,STHS具有在中性皂、低温皂和抗硬水皂配方中用作新皂基表面活性剂的潜质。     

Soap-based detergent formulations: XIX. Amphoteric alkylsuccinamide derivatives as lime soap dispersants

A series of amphoteric surfactants was synthesized by reaction of 1,3-propanesultone with N-alkyl-N′-(ω,ω-dimethylaminoalkyl)succinamides. The intermediate succinamides were prepared by reacting methyl N-alkylsuccinamates, obtained from alkylamines containing 8 to 18 carbon atoms, with N,N-dimethyl-1,3-propylenediamine or N,N-dimethylethylenediamine neat. The amphoterics were isolated as hygroscopic crystalline solids having superior lime soap dispersing ability, water solubility, and calcium ion stability. Detergency studies at 0.2% concentration (300 ppm water hardness) indicated good washing ability when used alone and excellent performance in combination with soap or in soap-silicate formulations. Presented at the AOCS Meeting, Cincinnati, 1975.     

Soap-based detergent formulations: XX. The physical and chemical nature of lime soap dispersions

Blends of soap and surfactants that possess good lime soap dispersing properties were dispersed in hard water. The turbidity of such dispersions varied depending on the type of dispersant used and also on the soap:dispersant ratio. Differences in coarseness of various dispersions could be measured empirically by filtration through a membrane of intermediate (1.2 μm) porosity. For determinations of the chemical composition of the dispersions a somewhat finer membrane (0.8 μm or less) was chosen, which retained most of the dispersed solids. Filter residues and filtrates were analyzed for sodium, calcium, magnesium and lime soap dispersing agents (LSDA). All of the calcium remained on the filter, whereas sodium was found primarily in the filtrate. Magnesium was held completely on the filter only if sufficient soap was present to tie up all Ca⁺⁺ and Mg⁺⁺. Analysis of the organic portion of the residues indicated that the soap:LSDA ratio found was the same as that used in the preparation of the original dispersion. On filtration through a fine membrane (0.05 μm) virtually all dispersed material was retained on the membrane. The filtrate possessed only slight activity in terms of surface tension and detergency, whereas the resuspended solids possessed high surface activity similar to the unfiltered dispersion. This indicates that the dispersed solids are the major source of surface activity. Presented at the AOCS Meeting, September 1975, Cincinnati.     

Dissolution Study of Salt of Long Chain Fatty Acids (Soap Scum) in Surfactant Solutions. Part I: Equilibrium Dissolution

Dissolution of calcium salt of a long chain fatty acid or soap scum is a major challenge for hard surface cleaners since soap scum forms when soap is exposed to hard water and has very low water solubility. In this paper, the aqueous equilibrium solubility of calcium octadecanoate (or calcium stearate) was measured as a function of pH as well as chelating agent (ethylenediaminetetraacetate disodium salt) and surfactant concentrations. Anionic, nonionic, and amphoteric surfactants were studied. The highest soap scum solubility was observed at high pH with an amphoteric surfactant. Under this condition, the chelant effectively binds calcium, and the stearate anion forms mixed micelles well with the amphoteric surfactant, which is in zwitterionic form at high pH.     

表面活性剂复配体系的分析

介绍了一种使用经典的分析技术定量测定液体皂、皂胶、洗衣皂及香皂中存在的皂类、脂肪酸、非离子表面活性剂及除肥皂以外的阴离子表面活性剂和两性表面活性剂混合物的分析方法。这种方法克服了分析混合表面活性剂系统时常常会碰到的问题。     

New amphoteric surfactants containing a phosphoric acid group: I. syntheses and physicochemical properties of sodium 2-(n-2-hydroxyalkyl-n-methylamino)ethyl hydrogen phosphate

A series of new amphoteric surfactants having a phosphoric acid group, a tertiary amino group and a 2-hydroxyalkyl group, sodium 2-(N-2-hydroxyalkyl-N-methyl-amino)ethyl hydrogen phosphates (alkyl: n-tetradecyl, n-hexadecyl, n-octadecyl), were prepared by an addition reaction of 1,2-epoxyalkanes to N-methylaminoethanol, followed by the introduction of a phosphoric acid group and neutralization with sodium hydroxide. The structures of these compounds were confirmed by spectroscopy and elemental analysis. The solubility in solvents, Krafft point, surface tension, critical micelle concentration (CMC), occupation area of the molecule at the surface of aqueous solutions and foaming power were measured. It was shown that a 2-hydroxyethyl group in a long alkyl chain seemed to behave as a hydrophobic part.     

Solubility and refractometric studies with copper valerate and caproate in nonaqueous solutions

The behavior of copper valerate and caproate in nonaqueous solutions has been investigated from solubility and refractometric methods. The apparent heat of solutions demonstrate the existence of micellar aggregates above the Krafft point. The refractive indices of soap solutions in hydrocarbons decrease whereas in alcohols increase with the increase in the soap concentration.     

Surface active N-acylglutamate: II. Physicochemical properties of long chain N-acylglutamic acids and their sodium salts

The physicochemical properties of long chain N-acylglutamic acids (AGA) and their sodium salts (AGS_n) are described. The solubility, Krafft point, pH value, critical micelle concentration, surface tension and foaming power were measured. The properties of the optically active AGA or AGS_n differed from those of the corresponding racemates, especially in solubility. The monosodium salts generally had high Krafft points, but monosodium N-oleoylglutamate had a low Krafft point. The monosodium salts hydrolyzed in the diluted aqueous solution to liberate the AGA. The aqueous solutions of the monosodium salts had low surface tensions and good foaming properties. The disodium salts were highly soluble in water, while surface tensions and foaming properties were inferior to those of the corresponding monosodium salts.     

Syntheses of sodium 2-(N-alkyl-N-methylamino)ethanephosphates and their physicochemical properties

A series of new amphoteric surfactants, sodium salts of 2-(N-alkyl-N-methylamino)ethanephosphates (alkyl: n-dodecyl, n-tetradecyl and n-hexadecyl) were prepared by reacting alkylbromides with N-methylaminoethanol, followed by addition of phosphoric acid groups and neutralization with sodium hydroxide. The structures of these compounds were confirmed by spectroscopy and elemental analysis. Physical properties such as Krafft point, isoelectric point, critical micelle concentration, occupation area of molecule at surface, foaming power and the effect of pH on surface activity were evaluated. These surfactants were found to exhibit zwitterionic characteristics in the pH range from approximately 5 to 9 and demonstrated good surface-active properties over a wide pH range (pH 4~10). Large occupation areas of the molecule at a surface in comparison with sodium dodecyl sulfate was noted as a characteristic feature of these surfactants.     

Soap-based detergent formulations: XXI. Amphoteric derivatives of fatty amides of aminoethylethanolamine1

Amides and 2-alkyl-N-(2-hydroxyethyl)-imidazolines were converted into various types of sulfated or sulfonated amphoteric lime soap dispersants. The alkylimidazolines could be readily hydrolyzed to give amidoamines. The cyclized amphoteric surfactants were generally superior in detergency and lime soap dispersing ability to analogous surfactants derived from amidoamines. Some of the cyclized surfactants, when formulated with soap and silicate builder, washed about as well under the test conditions as a control containing 50% sodium tripolyphosphate.     

Soap based detergent formulations. V. Amphoteric lime soap dispersing agents

A series of amphoteric surfactants was prepared by the reaction of 1,3-propanesultone with fat derived primary amines, N-methylalkylamines, N,N-dimethylalkylamines, and N-acyl-N′,N′-dimethyl-1,3-propanediamines. Both mono- and disulfopropylated derivatives of the primary amines were synthesized. All compounds were found to be excellent lime soap dispersing agents. The quaternary sulfobetaines were found to possess the best detergency properties both by themselves and when formulated with tallow soap with or without sodium silicate builder. The detergency performance of such formulations is ca. the same as that of a commercial phosphate-built detergent. Presented at the AOCS Meeting, New Orleands, May 1973. ARS, USDA.     

Liquid laundry detergents based on soap andα-sulfo methyl esters

It is well known that soap is one of the most effective cleaning agents in soft water. However, soap is equally notorious for some of its deficiencies, especially formation of soap scum due to the precipitation of calcium and magnesium soaps in hard water, low solubility in water, poor cleaning in cold water, greying of fabrics and dulling of hard surfaces such as ceramic tiles. Attributes of soap that should not be overlooked, especially in today’s environment, include an abundant and natural raw material supply (vegetable oils and fats) and excellent human and environmental safety profiles that are superior to most synthetic surfactants. Presented in part at an AOCS/CSMA Detergent Industry Conference, Hershey, Pennsylvania, October 31, 1989.     

Use of modified rosins in soap

Summary We have endeavored to show the advantages that rosins modified by hydrogenation, dehydrogenation, or polymerization have over ordinary rosins when used in soap. Ordinary rosin darkens in color upon oxidation. The modified rosins are not as susceptible to oxidation, and, therefore, soaps made using them do not darken in color to any greater extent than is normal for a soap made from the same fat stock but without rosin. The modified rosins when used as a replacement for part of the fat in soap making increase the rate of solubility of soap to a greater extent than do the ordinary rosins. They also show a slight advantage on the amount and stability of the lather. Hydrogenated rosin should be considered wherever germicidal value is desired since it contains a large proportion of tetra- and di-hydroabietic acids which have been shown by other investigators to have greater germicidal activity than the ordinary rosin acids or the fatty acids. The addition of modified rosins increase the wetting action of fatty acid soaps. It is indicated that up to 50% of modified rosin can be added to soap without decreasing detergent action, which, taken together with its other beneficial properties, makes it an ideal extender for fatty soap stocks. Chairman, Committee D-12 on Soap and Other Detergents of the American Society for Testing Materials.     

Determination of bicarbonate in soap products

Summary A method has been presented for the determination of bicarbonates in soap products based on the quantitative loss of CO₂ which occurs when bicarbonates are heated to 260°C. for 30 minutes. The method is subject to errors arising from the solubility of sodium bicarbonate in alcohol and the use of a large mathematical factor in calculating the bicarbonate content. In the absence of a more exact method the procedure gives results which are of great interest and value in soap analysis.