Saturated soaps

Foaming is a further key property controlled by carbon chain and maximum foaming is obtained from C12 saturated soaps. Generally, higher molecular weights will give lower foaming properties but introduction of unsaturations, or use of different counterions can affect both the volume and the nature of the foam. 

Finally, there is an interesting correlation between the values of 72(8/2) and molecular structure. For DC12AO the values of 72(8/2) are much greater than the Lorentzian value At 100° they are 5.5 for the neat phase and 4.5 for the middle phase. Sodium oleate (NaOl), which has a cis double bond in the middle of the chain, has considerably lower values of 72(8/2) for both middle (3.9) and neat (4.3) phases. The differences between the NaOl values and values found for saturated soaps are even greater. The lower values of 72(8/2) for NaOl indicate that the distribution of motions along the NaOl chain is more uniform. The double bond appears to act as another end, in effect making the chains much shorter. This is supported by the line width of NaOl (Table IV) which in the neat phase is roughly what one finds in a C12 — Cu chain. The double bond in the chain should have little effect in the middle phase. This appears to be borne out by both the 72(8/2) and line width data. The 72(8/2) for sodium elaidate... 

Ihe effect of a hydroxyl in the opposition was to increase the selective germicidal actiecies. Larson (U) found that Pnetxnooocci and Str tococci would not grow in the presence of even anall amounts (<0.1%) of sodiim ricinoleate. Larson and Nelson (H) reported that Pneimococci instantly lost their pathogeiicity on treatment with castor oil soap at a final dilution of 0.1%. Scarlet fever Streptococci was inhibited after 5 min in 0.5 % sodiim ricinoleate. Miller and Castles... 

Typically, soHd stabilizers utilize natural saturated fatty acid ligands with chain lengths of Cg—C g. Ziac stearate [557-05-1/, ziac neodecanoate [27253-29-8] calcium stearate [1592-23-0] barium stearate [6865-35-6] and cadmium laurate [2605-44-9] are some examples. To complete the package, the soHd products also contain other soHd additives such as polyols, antioxidants, and lubricants. Liquid stabilizers can make use of metal soaps of oleic acid, tall oil acids, 2-ethyl-hexanoic acid, octylphenol, and nonylphenol. Barium bis(nonylphenate) [41157-58-8] ziac 2-ethyIhexanoate [136-53-8], cadmium 2-ethyIhexanoate [2420-98-6], and overbased barium tallate [68855-79-8] are normally used ia the Hquid formulations along with solubilizers such as plasticizers, phosphites, and/or epoxidized oils. The majority of the Hquid barium—cadmium formulations rely on barium nonylphenate as the source of that metal. There are even some mixed metal stabilizers suppHed as pastes. The U.S. FDA approved calcium—zinc stabilizers are good examples because they contain a mixture of calcium stearate and ziac stearate suspended ia epoxidized soya oil. Table 4 shows examples of typical mixed metal stabilizers. 

Carboxylate soaps are most commonly formed through either direct or indirect reaction of aqueous caustic soda, ie, alkaH earth metal hydroxides such as NaOH, with fats and oils from natural sources, ie, triglycerides. Fats and oils are typically composed of both saturated and unsaturated fatty acid molecules containing between 8 and 20 carbons randomly linked through ester bonds to a glycerol [56-81-5] backbone. Overall, the reaction of caustic with triglyceride yields glycerol (qv) and soap in a reaction known as saponification. The reaction is shown in equation 1. 

The presence of a sufficientiy strong chelating agent, ie, one where K in equation 26 is large, keeps the concentration of free metal ion suppressed so that pM is larger than the saturation pM given by the solubiUty product relation (eq. 29) and no soHd phase of MX can form even in the presence of relatively high anion concentrations. The metal is thus sequestered with respect to precipitation by the anion, such as in the prevention of the formation of insoluble soaps in hard water. 

Properties are furthermore determined by the nature of the organic acid, the type of metal and its concentration, the presence of solvent and additives, and the method of manufacture. Higher melting points are characteristics of soaps made of high molecular-weight, straight-chain, saturated fatty acids. Branched-chain unsaturated fatty acids form soaps with lower melting points. Table 1 Hsts the properties of some soHd metal soaps. 

Liquid Diffusion The movement of liquids by diffusion in soUds is restricted to the equihbrium moisture content below the point of atmospheric saturation and to systems in which moisture and solid are mutually soluble. The first class apphes to the last stages in the diying of clays, starches, flour, textiles, paper, and wood the second class includes the diying of soaps, glues, gelatins, and pastes. 

Suitable organic solvents, such as ether, benzene, naphtha and the like, are more soluble than in water. This makes it possible to separate them from other substances which may accompany them in the water solution but which are not soluble in the solvents employed. Hence, one application of solvent extraction is the analytical determination of unsaponifiable oils and waxes in admixture with fatty material by submitting the mixture to vigorous saponification with alcoholic potash or, if necessary, sodium ethylate, and to dilute the product with water and extract with petroleum ether. The soaps remain in the aqueous solution while the unsaponifiable oils and waxes dissolved in the ether. The addition of a salt to an aqueous solution prior to extraction is sometimes practiced in some processes. In older processes, SOj is employed in the separation of aromatic and highly saturated hydrocarbons, taking advantage of the much greater solubility of the solubility of the aromatics and... 

The solubility of calcium carbonate is such that in a saturated solution the product of ion concentrations [Ca+2][C0 2] is 5 X I0 B. Though this may seem quite small, it is large enough to be important to man, especially if he lives in a region of the earth where there are extensive limestone deposits. Calcium carbonate can be dissolved in water, especially if it contains much dissolved C02. This is objectionable because soap added to water which contains even traces of Ca+2 forms a precipitate of calcium stearate. This is the ring that is so difficult to remove from the bathtub. 

The hydrolysis of a fat to a soap by reaction with an alkali. Saturated steam ... 

The raw materials for the manufacture of soap, the alkali salts of saturated and unsaturated C10-C20 carboxylic acids, are natural fats and fatty oils, especially tallow oil and other animal fats (lard), coconut oil, palm kernel oil, peanut oil, and even olive oil. In addition, the tall oil fatty acids, which are obtained in the kraft pulping process, are used for soap production. A typical formulation of fats for the manufacture of soap contains 80-90% tallow oil and 10-20% coconut oil [2]. For the manufacture of soft soaps, the potassium salts of fatty acids are used, as are linseed oil, soybean oil, and cottonseed oil acids. High-quality soap can only be produced by high-quality fats, independent of the soap being produced by saponification of the natural fat with caustic soda solution or by neutralization of distilled fatty acids, obtained by hydrolysis of fats, with soda or caustic soda solutions. Fatty acids produced by paraffin wax oxidation are of inferior quality due to a high content of unwanted byproducts. Therefore in industrially developed countries these fatty acids are not used for the manufacture of soap. This now seems to be true as well for the developing countries. 

Saturated hydrocarbons (waxes), fatty acids, metal soaps, fatty acid amides and esters (primarily Cig-Cis) act as internal lubricants, fluoro elastomers as external lubricants. Many other polymer additives, e.g. antistatic agents, antifogs, antioxidants, UV stabilisers, etc., act as lubricants in the barrel of the extruder once they are in the liquid form. 

The collector used in this experiment was sodium oleate at additions of 300 g/t. In addition to sodium oleate, other fatty acid collectors were examined. The results are given in Table 24.10. From these data, the saturated fatty acid soap was a poor collector for monazite, as well as sodium laurate. 

W. Narath, G. Omoski, J. Corr, Enhanced processing of synthetic bar compositions comprising amphoterics based on minimal levels of fatty acid soap and minimum ratios of saturated to unsaturated soap, US Patent No. 6 121 216 (2000). 

Add 25 mL saturated NaCI solution to the mixture in the beaker. The soap is not very soluble and will appear as small clumps. 

No data are as yet available on the effect of length of tail on the emulsion size. As has already been noted (p. 46) fatty acids with short hydrocarbon tails are very water soluble and the sodium soaps soluble to a greater degree, interfacial adsorption is consequently small. Thus the concentration required to produce a saturated film at the oil-water interface will be correspondingly greater. This necessitates a high sodium ion concentration in the... 

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