Alkali metal soaps

An emulsifying agent generally produces such an emulsion that the liquid in which it is most soluble forms the external phase. Thus the alkali metal soaps and hydrophilic colloids produce O/W emulsions, oil-soluble resins the W/O type (see emulsion). 

One may rationalize emulsion type in terms of interfacial tensions. Bancroft [20] and later Clowes [21] proposed that the interfacial film of emulsion-stabilizing surfactant be regarded as duplex in nature, so that an inner and an outer interfacial tension could be discussed. On this basis, the type of emulsion formed (W/O vs. O/W) should be such that the inner surface is the one of higher surface tension. Thus sodium and other alkali metal soaps tend to stabilize O/W emulsions, and the explanation would be that, being more water- than oil-soluble, the film-water interfacial tension should be lower than the film-oil one. Conversely, with the relatively more oil-soluble metal soaps, the reverse should be true, and they should stabilize W/O emulsions, as in fact they do. An alternative statement, known as Bancroft s rule, is that the external phase will be that in which the emulsifying agent is the more soluble [20]. A related approach is discussed in Section XIV-5. 

Ionic LCs are interesting systems because they combine the properties of LCs with those of ionic liquids. Although alkali metal soaps were among the first thermotropic LCs to be systematically studied, ionic liquid crystalline derivatives have been reported less frequently than those based on neutral molecular and macromolecular species [39]. When the halide of [AuX(CNR)] complexes is substituted by a second isocyanide, ionic complexes [Au(CNR)2][Y] [R = C6H40C H2 + i (27a),... 

Nature of the emulsifying agent Alkali-metal soaps favour the formation of O/W emulsions, whereas heavy-metal soaps favour the formation of W/O emulsions. O/W emulsions in the middle concentration region stabilised by alkali-metal soaps can often be broken, and even inverted into W/O emulsions, by the addition of heavy-metal ions. 

Anionic surfactants are negatively charged in an aqueous solution (i.e., -COO-, -OSOj), and widely used because of their cost and performance. Sodium lauryl sulfate, the main component of which is sodium dodecyl sulfate, is highly soluble in water and commonly used to form oil-in-water (O/W) emulsions. Reacting an alkali hydroxide with a fatty acid (e.g., oleic acid) can produce alkali metal soaps (e.g., sodium oleate). Careful attention must be paid to the pH of the dispersion medium and the presence of multivalent metals (see Section 4.2.5). Alkali earth metal soaps (e.g., calcium oleate) produce stable water-in-oil (W/O) emulsions because of their low water solubility and are produced by reacting oleic acid with calcium hydroxide. Triethanolamine stearate produces stable O/W emulsions in situ by reacting triethanolamine in aqueous solution with melted stearic acid at approximately 65°C (e.g., vanishing cream). 

Hydrogenated castor oil retains the hydroxyl group. Its lithium and other alkali metal soaps are outstanding thickeners, providing a gel structure important to the multipurpose greases that are used for automotive, truck, aviation, railroad, and industrial applications. Insolubility of the hydroxyl stearic soap is the key to the formation of a stable and diuable gel strueture. Castor oil is also often used in cosmeties as simple esters, mono- and diglyeerides, glycol esters, and hydroxyl stearates. 

The lather shave cream is a concentrated dispersion of alkali metal soap in a glycerol-water mixture. This formulation has adequate physical stability, particularly if the manufacturing process is carefully optimised. Phase separation of the formulation may occur at elevated temperatures. 

The most commonly used soaps are the alkali metal soaps, RCOOX, where X is sodium, potassium or ammonium, and R is generally between Cio and 20-... 

The situation is quite different, if we admit association polymers as legitimate polymers. An outstanding example is the class of the alkali and earth alkali metals soaps of long chain fatty acids. Their polymorphic behavior is well established (1), and is ascribed to the Increasing mobility of the alkane groups with increasing temperature. Typical examples are shown on Table 2. 

Soaps are unstable in acid media since the free fatty acid formed under these conditions will tend to be insoluble. Alkali-metal soaps are used in the preparation of oil-in-water emulsions, which are most stable in alkaline solution (above pH 10) and which crack in acid media and in the presence of calcium ions. Water-in-oil emulsions may be prepared using calcium, zinc, magnesium and aluminium salts of the higher fatty acids-the so-called metallic soaps. The combination of amine salts such as triethanolamine, with fatty acids gives the amine soaps. These soaps yield oil-in-water emulsions which are more stable than those prepared with alkali-metal soaps, although they still tend to crack in acid conditions. 

Chem. Descrip. Hydrogenated menhaden oil CAS 68002-72-2 EINECS/ELINCS 297-485-6 Uses Used in mfg. of alkali metal soaps, monoglycerides, textile auxiliaries, greases, personal care prods. activator for NR, SR Properties Solid acid no. 5 max. iodine no. 5 max. sapon. no. 186-201 100% cone. 

Uses Used in mfg. of alkali metal soaps, monoglycerides, textile auxiliaries, greases... 

The alkali metal soaps have been used for at least 2300 years. Their use as articles of trade by the Phoenicians as early as 600 b.c. has been documented. They were also used by the Romans, although it is generally felt that their manufacture was learned from the Celts or some Mediterranean culture. Early soap producers used animal fats and ashes of wood and other plants containing potassium carbonate to produce the neutralized salt. As the mixture of fat, ashes, and water was boiled, the fat was saponified to the free fatty acids, which were subsequently neutralized. 

Such water, and also that containing salts of multipositive metals, (usually sulphates), is said to be hard since it does not readily produce a lather with soap. Experiments with alkali metal salts can be performed to verify that the hardness is due to the presence of the multipositive metal ions and not to any of the anions present. The hardness due to calcium and magnesium hydrogencarbonates is said to be temporary since it can be removed by boiling ... 

Because of the different vulcanization chemistry involved in each commercial ACM, a vulcanization system specific to the cure site present has to be adopted. Many cure systems for labile chlorine containing ACM have been proposed (45). Among these the alkali metal carboxylate—sulfur cure system, or soap—sulfur as it is called in the United States, became the mainstay of acryflc elastomer technology in the early 1960s (46), and continues to be widely used. 

Fatty-acid soaps Alkali, alkaline earth, and other metal soaps sodium stearate aluminum stearate Gear oils paper stock paper sizing glue solutions... 

Alkali-metal phosphides, 19 59 Alkali metals, 14 248 20 597, 598 as anionic initiators, 14 245-248 cation binding of, 24 41 soap and, 22 723... 

P.R.66, a barium salt, is sold only in the USA. The pigment is also available as an aluminum oxide hydrate precipitate. Its shade is considered a brilliant medium red, which is somewhat yellower than that of the chemically related P.R.67. Commercial types of P.R.66 are very transparent. The pigment is highly sensitive to acid, alkali, and soap. Its fastness to organic solvents is poor, its fastness to overcoating as well. P.R.66 exhibits limited lightfastness. Its main application is in metal deco printing. 

P.R.67, a barium salt, is also available in the form of an aluminum oxide hydrate precipitate. Its shade is bluer compared to the chemically related P.R.66, it is referred to as a bright bluish red. Commercial types are transparent and tinctorially strong. P.R.67 is used especially in metal deco printing. The prints do not tolerate acid, alkali, or soap. They show only limited fastness to organic solvents and to... 

As with other alkali metals, potassium compounds have many uses. For example, almost all of the compound potassium chloride is used in fertilizers. Currently potassium chloride is mined or derived from seawater. Many years ago, potassium was secured for human use by burning wood and plant matter in pots to produce an ash called potash, which was mostly potassium carbonate and used as a caustic, mainly for making soap when mixed with fats. 

The carboxyl group reacts with metal oxides, hydroxides, or salts to form rosin soaps or salts (resinates). The soaps of alkali metals, such as sodium and potassium, are useful in paper sizing and as emulsifiers in rubber polymerization. 

A better method for studying the alkali metal cation-soap anion interaction on the surface, according to Weil (58), is to assume a similarity between surface behavior and solution behavior and to use the activity coefficient of the solute in the solution as the parameter to account for surface behavior. By plotting activity coefficients as a function of the molality for the salts of the alkali metals (7, 26), the resulting order of the curves of the weak acids (formates, acetates, hydroxides) is the reverse of that found for the strong acids (chlorides, bromides, nitrates, chlorates, sulfates). The activity curves of the acetate salts can be used as the counterparts for the long-chain fatty acid salts, while those for the chlorides can be the analogs of the alkyl sulfates. The scheme is speculative in that the fatty acid and alkyl sulfate salts micellize, and acetate and chloride do not. 

Micellar systems (i.e.,. Shenoy 1984 Ohlendorf Brunn) as well as other colloidal systems (polyphosphates (Hunston), tri-n-butyl-tin-fluoride, e.g. Dunn Evans) come under the heading surfactants . It is necessary to differentiate soaps into anionic, cationic, and non-ionic types. Among the anionic types one can find, for instance, alkali metals and ammonium salts consisting of various fatty acids, which were... 

ALKALI. A term that was originally applied to the hydroxides and carbonates of. sodium and potassium but since has been extended to include tire hydroxides and carbonates of the other alkali metals and ammonium. Alkali hydroxides are characterized by ability to fomi soluble soaps with fatly adds, to restore color to litmus which has been reddened by acids, and to unite with carbon dioxide to form soluble compounds. See also Acids and Bases. 

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