Lanoline

The cleaning process proceeds by one of three primary mechanisms solubilization, emulsification, and roll-up [229]. In solubilization the oily phase partitions into surfactant micelles that desorb from the solid surface and diffuse into the bulk. As mentioned above, there is a body of theoretical work on solubilization [146, 147] and numerous experimental studies by a variety of spectroscopic techniques [143-145,230]. Emulsification involves the formation and removal of an emulsion at the oil-water interface the removal step may involve hydrodynamic as well as surface chemical forces. Emulsion formation is covered in Chapter XIV. In roll-up the surfactant reduces the contact angle of the liquid soil or the surface free energy of a solid particle aiding its detachment and subsequent removal by hydrodynamic forces. Adam and Stevenson s beautiful photographs illustrate roll-up of lanoline on wood fibers [231]. In order to achieve roll-up, one requires the surface free energies for soil detachment illustrated in Fig. XIII-14 to obey... 

A surfactant mixture having an HLB number of 8 should give a good W/O emulsion in which the oil phase is lanolin. Suggest two possible surfactant mixtures that you, an aspiring cosmetic chemist, might use you have been told that your formulations must contain 10% cetyl alcohol. 

Lanosterol is one component of lanolin a mixture of many substances that coats the wool of sheep... 

In certain brilliantine compositions, vegetable and animal oils are used as substitutes for mineral oil. In these systems, because of their potential for rancidity, antioxidants must be included. Other alternatives to mineral oils that have found utiHty in brilliantines are the polyethylene glycols which come in a variety of solubiHties and spreading properties. Use of these materials offers the advantage of chemical stabiHty to rancidity. Other additives found in brilliantines to improve their aesthetics include colorants, fragrance, medicated additives, lanolin, and fatty acid esters. 

Iodine is extensively used in a variety of forms as both an antiseptic and a disinfectant. lodophors, usually nonionic surfactants (qv) complexed with iodine, were developed for more readily usable iodine-based antiseptics and disinfectants. These are used as disinfectants in dairies, laboratories, and food processing (qv) plants, and for sanitation of dishes in restaurants. The reaction product of lanolin and iodine shows utiHty as a germicide (149). 

Mildness nd Skin Additives. The increased frequency of bathing and the changing consumer need has necessitated the development of products having skin care benefits. In addition to the two most common additives, fatty acid and glycerol, there is a wealth of other additives which are frequendy used. Examples include lanolin, vitamin E, aloe vera gel, mineral oil, and baking soda. 

Lanolin alcohols are obtained by saponification of purified wool grease, a mixture of high molecular esters that is recovered in wool (qv) scouring. Ethoxylation of purified lanolin alcohols yields a full series of lipophilic and hydrophilic nonionic emulsifiers whose largest use is in cosmetic preparations. Manufacturers include Amerchol, Croda, ICI, Henkel Corporation, Westbrook Lanolin, Witco, and Pulcra, SA. 

Suspensions of oil in water (32), such as lanolin in wool (qv) scouring effluents, are stabilized with emulsifiers to prevent the oil phase from adsorbing onto the membrane. Polymer latices and electrophoretic paint dispersions are stabilized using surface-active agents to reduce particle agglomeration in the gel-polarization layer. 

Grease Refining and Fractionation. Lanolin to be used in pharmaceuticals and cosmetics must conform to strict requirements of purity, such as those in the U.S. and British Pharmacopoeias (181,182). These include specifications for the maximum allowable content of free fatty acids, moisture, ash, and free chloride. Lanolin intended for certain dermatological appHcations may have to meet further specifications in relation to free-alcohol and detergent contents (183,184). 

Uses of Wool Grease. The uses of wool grease, lanolin, and lanolin derivatives are many, ranging from pharmaceuticals and cosmetics (qv) to printing inks (qv), mst preventatives, and lubricants (see Lubrication and lubricants). 

In pharmaceutical uses, the general inertness of lanolin and its derivatives, together with their ease of emulsification (185), have been important criteria. These properties are also important in cosmetics, but with emphasis also on the abiHty to absorb large quantities of water or, after suitable modification, to stabilize o/w emulsions. 

The anticorrosion properties of lanolin have been utilized over a considerable period, and the product has the status of a temporary corrosion inhibitor (186) (see Corrosion and corrosion control). There is probably potential for greater use of the poorer grades of lanolin for long-term storage and protection of machine parts. Other uses have been reviewed in detail (182). 

Fig. 2. Effect of wash temperature on removal of sebum, O lanolin, and lard from cotton (0.25% built detergent) (48). D, Represents sebum removal...

This type of corrosion can take place on any new surface of zinc and is best prevented by storing the metal in a dry, airy place until a protective layer has been formed. Zinc which has been properly aged in this way is safe against white-rust formation. Various methods are employed to prevent white rust. A chromate treatment is widely used for zinc-plated articles and for galvanised sheet, and occasionally for zinc die castings. Fatty substances, such as oils or lanolin, are sometimes used to protect larger items. 

Those deposited in the cold from a solvent usually consist of lanolin or petrolatum mixtures in such solvents as white spirit or coal tar naphtha. The film is thinner than other soft films deposited by different methods. 

The smearing types of material are usually lubricating grease compositions, i.e. blends of soaps and lubricating oil, biit may be mixtures containing petrolatum, oil, lanolin or fatty material. They are softer than the hot-dip materials to pOrmit cold application by smearing. 

Hot-dipping soft Petrolatum, lanolin. Dipping in Solid, thick, waxy... 

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