Fatty-acid salts

It has to be admitted that the situation regarding fatty acid salts is not well established. Indeed there is much ambiguity in the literature with the terms stearic acid and stearates often being used interchangeably. As discussed earlier, some form of salt is the effective coating material after a fatty acid has reacted with the surface of fillers, but a part salt has to be involved if the acid is to be thought of as reacted onto the filler surface. A full salt will only he weakly attached. 

Full fatty acid salts themselves, are frequently used as polymer additives, usually as processing aids and acid scavengers. Both Gilbert and co-workers [30] and Hornsby and Watson [31] have indicated that such fatty acid salts can be used to beneficially pre-treat fillers, with the effectiveness depending on the metal present in the salt and the filler. Fatty acids and their salts when used as additives may adsorb onto the surface of untreated fillers and this has to be taken into account when developing formulations [32]. Fulmer and co-workers, also claim that using fatty acid salts as additives can be as effective as pre-coating fillers [22]. More work is needed to clarify this area. 

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Additives acting on the pour point also modify the crystal size and, in addition, decrease the cohesive forces between crystals, allowing flow at lower temperatures. These additives are also copolymers containing vinyl esters, alkyl acrylates, or alkyl fumarates. In addition, formulations containing surfactants, such as the amides or fatty acid salts and long-chain dialkyl-amines, have an effect both on the cold filter plugging point and the pour point. 

Mann B and Kuhn H 1971 Tunneling through fatty acid salt monolayers J. Appl. Phys. 42 4398-405... 

Emulsifiers. Removing the remover is just as important as removing the finish. For water rinse removers, a detergent that is compatible with the remover formula must be selected. Many organic solvents used in removers are not water soluble, so emulsifiers are often added (see Emulsions). Anionic types such as alkyl aryl sulfonates or tolyl fatty acid salts are used. In other appHcations, nonionic surfactants are preferred and hydrophilic—lipophilic balance is an important consideration. 

Serious attempts to use LB films in commercial appHcations include the use of lead stearate as a diffraction grating for soft x-rays (64). Detailed discussion on appHcations of LB films are available (4,65). From the materials point of view, the abiHty to build noncentro symmetric films having a precise control on film thickness, suggests that one of the first appHcations of LB films may be in the area of second-order nonlinear optics. Whereas a waveguide based on LB films of fatty acid salts was reported in 1977, a waveguide based on polymeric LB films has not yet been commercialized. 

The combined soap (CS) is a mix of fatty acids salts (FAS) and different surfactants. The surfactants usually sodium acylisethionats (AIST), which ai e derivates of fatty acids, as a mle, coconut oil or lauric fraction. 

The 18-8 stainless steels pit severely in fatty acids, salt brines, and salt solutions. Often the solution for such chronic behavior is to switch to plastics or glass fibers that do not pit because they are made of more inert material. 

Accelerated sulphur systems also require the use of an activator comprising a metal oxide, usually zinc oxide, and a fatty acid, commonly stearic acid. For some purposes, for example where a high degree of transparency is required, the activator may be a fatty acid salt such as zinc stearate. Thus a basic curing system has four components sulphur vulcanising agent, accelerator (sometimes combinations of accelerators), metal oxide and fatty acid. In addition, in order to improve the resistance to scorching, a prevulcanisation inhibitor such as A -cyclohexylthiophthalimide may be incorporated without adverse effects on either cure rate or physical properties. 

Potassium sorbate is a polyunsaturated fatty acid salt. It is used to inhibit molds, yeasts, and fungi in many foods, including cheese, wine, and baked goods. It is the potassium salt of sorbic acid. 

Ether carboxylates are used not only in powdered detergents but in liquid laundry detergents for their hard water stability, lime soap dispersibility, and electrolyte stability they improve the suspension stability and rheology of the electrolyte builder [130,131]. Formulations based particularly on lauryl ether carboxylate + 4.5 EO combined with fatty acid salt and other anionic surfactants are described [132], sometimes in combination with quaternary compounds as softeners [133,163]. Ether carboxylates show improved cleaning properties as suds-controlling agents in formulations with ethoxylated alkylphenol or fatty alcohol, alkyl phosphate esters or alkoxylate phosphate esters, and water-soluble builders [134]. 

Polymer films can be made antistatic with a-sulfonated fatty acid salts and esters [94]. For example, an antistatic additive for polypropylene manufacture can be prepared from potassium methyl a-sulfopalmitate, styrene oligomer, and 2-propanol [95]. The treatment of synthetic fibers and fabrics with a-sulfo-... 

The procedure started, as in the previous case, with the deposition of the LB film of fatty acid salts with bivalent metals. Then the fihn was exposed to the atmosphere of H2S... 

K Morimoto, T Nakamura, K Morisaka. (1989). Effect of medium-chain fatty acid salts on penetration of a hydrophilic compound and a macromolecular compound across rabbit corneas. Arch Int Pharmacodyn 302 18-26. 

Emulsifiers have been used to prepare oil-external emulsion drilling fluids. Surfactants used as emulsifiers include fatty acid salts, fatty acid amides, petroleum sulfonates, and lignosulfo-nates. 

In this connection it may be of interest to mention that a wide variety of reagents such as the fatty acid salts of Cu11, Mn, Co, Ni, and Al, and magnesium acetylacetonate were reported to have no effect upon the rate of decomposition of w-octadecyl azidoformate in diphenyl ether solution 58>. 

The formation of an ester from an alcohol and an acid is an equilibrium reaction. The reverse reaction can be promoted by removing the acid from the reaction mixture, for example by treating it with NaOH. Animal fats are converted to soaps (fatty acid salts) and glycerine (a trialcohol) in this manner. 

Wet anti-tack agents can be soap or detergent solutions or suspensions of the dry agents in water. For example, dissolved polymers with non-ionic surface active agents which form a thin layer of polymer on unvulcanised rubber sheets magnesium stearate in water zinc stearate dispersion and aqueous dispersions of fatty acid salts. 

Zinc fatty acid salts/soaps Fatty acid esters... 

Durand, R. (1948) Investigations on hydrotropy. The solubility of benzene, hexane and cyclohexane in aqueous solutions of fatty acid salts. Compt. Rend. 226, 409 -10. 

Mann B, Kuhn H (1971) Tunneling through fatty acid salt monolayers. J Appl Phys... 

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