Formulation of Soaps

AOS is a useful surfactant system for the formulation of soap bars. The effect of AOS on the Krafft temperature of soap is shown in Table 27 AOS lowers the Krafft temperature of soap. AOS can also be used to cosolubilize soap in water thereby reducing the waste of insoluble soap as shown in Table 28. 

Monoterpenes are widely used in the pharmaceutical, cosmetic and food industry as active components of drugs and ingredients of artificial flavours and fragrances [1]. Camphene is converted to isobomeol and bomeol that are used in formulation of soaps, cosmetic perfumes and medicines, as well as in the industrial production of camphor [2], which is used as an odorant/flavorant in pharmaceutical, household and industrial products [7]. Traditionally, homogeneous catalysts, e.g sulphuric acid, are used, but the effluent disposal leads to environmental problems and economical inconveniences. These problems can be overcome by the use of solid acid catalysts. USY zeolite [3], heteropolyacids [4,5] and sulfonic acid surface-functionalised silica [6] have also been used for the camphene hydration. 

Bar Soap Additives. There are a variety of additives that may be formulated into soap bars to provide additional consumer benefits or modify the performance of the products. 

These surfactants, in conjunction with soap, produce bars that may possess superior lathering and rinsing in hard water, greater lather stabiUty, and improved skin effects. Beauty and skin care bars are becoming very complex formulations. A review of the Hterature clearly demonstrates the complexity of these very mild formulations, where it is not uncommon to find a mixture of synthetic surfactants, each of which is specifically added to modify various properties of the product. Eor example, one approach commonly reported is to blend a low level of soap (for product firmness), a mild primary surfactant (such as sodium cocoyl isethionate), a high lathering or lather-boosting cosurfactant, eg, cocamidopropyl betaine or AGS, and potentially an emollient like stearic acid (27). Such benefits come at a cost to the consumer because these materials are considerably more expensive than simple soaps. 

Soap as used in personal cleansing products has a long safe history of use. Modem soaps have been specifically formulated to be compatible with skin and to be used on a daily basis with minimal side effects. Excessive use of soap for skin cleansing can dismpt the natural barrier function of skin through the removal of skin oils and dismption of the Hpid bdayer in skin. This can result in imperfect desquamation or a dry appearance to skin and cause an irritation response or erythema, ie, reddening of the skin. Neither of these is a permanent response and the eHcitation of this type of skin reaction depends on the individual s skin type, the product formulation, and the frequency of use. 

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. 

Sodium alcohol sulfates are also used in the formulation of synthetic soaps and paste hand cleaners, commonly together with other surfactants and as tablet disintegrators in the case of sodium dodecyl sulfate. Sodium, but preferably ammonium and alkanolamine salts, is also used in liquid soaps. 

Due to the good lime soap dispersing properties it is possible to improve the foaming properties of hard water-susceptible surfactants. Improvement of the formulation of a fatty acid soap by laureth-17 carboxylic acid, sodium salt [57,62], and an amidether carboxylate [62] has been described. 

Fat absorption has been found to be less efficient in infants than in adult humans (60-63). Thus, the potential for formation and precipitation of calcium soaps inhibiting the absorption of calcium would appear to be greater. Furthermore, formulation of products to best promote both fat and calcium utilization by bottle fed infants would appear to be a desirable, obtainable objective. 

Adsorption inhibitors act by forming a film on the metal surface. The action of traditional oil-based red lead paint formulations presumably involves the formation of soaps and the precipitation of complex ferric salts that reinforce the oxide film. There has been substantial interest in recent years in development of replacements for lead-based and chromate-based inhibitor systems. Adsorption inhibitors based on pol3rmers have been of particular interest. In this volume, Johnson et al. and Eng and Ishida discuss inhibitors for copper 2-undecylimidazole is shown to be effective in acid media, where it suppresses the oxygen reduction reaction almost completely. Polyvlnyllmidazoles are shown to be effective oxidation inhibitors for copper at elevated temperatures. Also in this volume, Chen discusses the use of N-(hydroxyalkyl)acrylamide copolymers in conjunction with phosphate-orthophosphate inhibitor systems for cooling systems. 

Several commercial brands of soap are especially formulated and labeled for use on garden vegetables. Some of these may be mixed with other pesticides to increase the effectiveness of both. Commercially labeled soaps are the only soaps recommended for use in the home garden. Be sure to use them only as recommended on the label. 

Wastewaters from the manufacturing, processing, and formulation of organic chemicals such as soaps and detergents cannot be exactly characterized. The wastewater streams are usually expected to contain trace or larger concentrations of all raw materials used in the plant, all intermediate compounds produced during manufacture, aU final products, coproducts, and byproducts, and the auxiliary or processing chemicals employed. It is desirable, from the... 

This phenomenon of self-emulsification was first observed by Johannes Gad in 1878 when he gently layered a solution of lauric acid on top of an aqueous alkaline solution, thereby making a soap in situ but also forming an emulsion without the aid of external agitation. A laboratory curiosity for the next 50 or so years, the principle became recognized as being valuable for the formulation of herbicides and insecticides such as DDT. The concentrate could be reconstituted with ditch water and sprayed without the need to carry water to the site. 

Lithium hydroxide monohydrate. CAS l3IO-65-2. LiOH H 0 loses water at I0LC. LiOH nidus at 450 C. The compound is soluble in water. The compound is used in the formulation of lithium soaps used in multipurpose greases also in the manufacture of various lithium salts and as an additive lo the electrolyte of alkaline storage bailerics. LiOH also is an efficient, light-weight absorbent for carbon dioxide. 

The chemical potentials measured so far do not allow the formulation of thermodynamic criteria for the formation of lyotropic mesophases. Some qualitative remarks, however, can be made. Of particular interest are Ekwall s studies of the relations between the water binding of the mesophases, their ionization, x-ray parameters, and vapor pressures (4). For common soaps at room temperature mesophases can be observed only in the presence of amounts of water that hydrate the ionic and polar groups. Hydration is therefore characteristic of aqueous lyotropic mesophases as well as micellar systems (1, 2, 3). The binding of counterions to the micelles and to the mesoaggregates seems to be of a similar electrostatic nature. The addition of NaCl greatly affects the lamellar phase D and, to a lesser extent, phase E in these phases the counterions are more strongly bound than by micelles in the solution... 

---