Stability, carboxylic acid-soap

Three generations of latices as characterized by the type of surfactant used in manufacture have been defined (53). The first generation includes latices made with conventional (/) anionic surfactants like fatty acid soaps, alkyl carboxylates, alkyl sulfates, and alkyl sulfonates (54) (2) nonionic surfactants like poly(ethylene oxide) or poly(vinyl alcohol) used to improve freeze—thaw and shear stabiUty and (J) cationic surfactants like amines, nitriles, and other nitrogen bases, rarely used because of incompatibiUty problems. Portiand cement latex modifiers are one example where cationic surfactants are used. Anionic surfactants yield smaller particles than nonionic surfactants (55). Often a combination of anionic surfactants or anionic and nonionic surfactants are used to provide improved stabiUty. The stabilizing abiUty of anionic fatty acid soaps diminishes at lower pH as the soaps revert to their acids. First-generation latices also suffer from the presence of soap on the polymer particles at the end of the polymerization. Steam and vacuum stripping methods are often used to remove the soap and unreacted monomer from the final product (56). 

Schulze [51] described an extensive study on C12-C14 ether carboxylic acid sodium salt (4.5 mol EO) in terms of surface tension, critical micelle concentration (CMC), wetting, detergency, foam, hardness stability, and lime soap dispersing properties. He found good detergent effect compared to the etho-xylated C16-C18 fatty alcohol (25 mol EO) independent of CaCl2 concentration, there was excellent soil suspending power, low surface tension, and fewer Ca deposits than with alkylbenzenesulfonate. 

Addition of chemicals without careful consideration may break an emulsion. An emulsion prepared with ionic surfactants should not be mixed with chemically incompatible materials of opposite charge. The pH of the emulsion should be alkaline if the emulsion is made with alkali soaps. At an acidic pH, the carboxylate ion of the soap is converted to the carboxylic acid, which is not water-soluble and an emulsifying agent. An alkali-soap stabilized O/W-type emulsion may be inverted to a W/O-type emulsion by adding a divalent electrolyte. The carboxylate ion reacts with the divalent electrolyte to form an alkali earth soap that is an oil-soluble surfactant. Addition of a common electrolyte to an emulsion prepared with ionic surfactants suppresses the ionization according to the Le Chatelier rule (e.g., ammonium oleate and ammonium chloride). The presence of noninteractive electrolytes in the emulsions alters the polar nature of the interfacial film. For example, the... 

In this article we evaluate interactions in a system stabilized with an ionic surfactant and with a carboxylic acid as the cosurfactant. Such a system is distinguished from the common soap/alcohol stabilizer combinations by the fact that the soap/acid system does not require a minimum water concentration to dissolve the soap. 

Owing to metal chlorides titration by the coulometric method, and carboxylic acid titration by the potentiometric method, it is possible to follow the metal soaps consumption during thermomechanical heat treatments. This new technique provides a better understanding of the stabilization mechanisms of PVC with the calciumr-zinc system, and offers a better explanation of synergistic effects between metal soaps and secondary stabilizers such as epoxidized soya-bean oil, a-phenylindole, and butanediol-p-aminocroto-nate. The influence of these last stabilizers on zinc chloride formation enables us to classify them into short- and longterm stabilizers. 

Knowing the quantity of metal chlorides and carboxylate acid liberated during thermomechanical heat treatments permits a better understanding of the stabilization mechanisms of metal soaps. This study confirms that the action time of stabilizer TA includes not only the primary... 

For the evaluation of the foamability of a surfactant the bulk concentration is used at which the relative rate of foam collapse is equal to 50% of its formation (cw °). The cw ° values determined from foam formation isotherms of a number of products are given in Table 6.1. As it is seen, typical representatives of anionics (sodium dodecyl sulphate), cationics (cetyl trimethyl ammonium bromide) and nonionics (ethoxylated alkylphenols) give bubble foams at very low concentrations, and the foam stability of ionic surfactants does not differ much from that of nonionics. For anionics, the highest concentrations are required for soaps of higher carboxylic acids. 

PEG-15 phytosterol PEG-20 phytosterol PEG-25 phytosterol PEG-30 phytosterol Stearamine oxide stabilizer, foam prods. Isostearamidopropylamine oxide stabilizer, foam SBR latex systems Ammonium stearate stabilizer, foam shampoo Apricotamide DEA Cl 2-14 alkyl dimethyl betaine Cocamidopropyl betaine Cocamidopropyl lauryl ether Cocamine oxide Disodium lauroamphodiacetate Laureth-6 carboxylic acid Linoleamide DEA Myristamine oxide Palm kernelamide DEA PEG-3 cocamine PEG-3 lauramide Polyquaternium-7 Undecylenamide DEA stabilizer, foam skin care Disodium lauroamphodiacetate Hydrolyzed wheat gluten Olivamidopropyl betaine stabilizer, foam soaps PEG-40 lanolin PEG-85 lanolin... 

Mixed metal stabilizers are the salts of long chain carboxylic acids, also addressed as metal soaps. Actually, the hydrogen chloride evolved in the course of degradation of PVC is scavenged by the addition of metal soaps in the same sense as a buffer substance acts in ordinary acid base chemistry. However, the action is more complicated, as the affectivity is dependent on the nature of the metal ion. Moreover, synergistic effects using tin or cadmium, together with barium or calcium salts, have been observed. This behavior is attributed to the formation of complexes. 

The COONa group in the ether carboxylate has a positive effect on the lime soap dispersing properties [61,64] (Table 4). Stroink [61] and Meijer [64] also describe the good acid, alkali, and electrolyte stability of some ether carboxy-... 

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]. 

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