Solubilization, additives

Block copolymers are widely used industrially. In the solid and rubbery states they are used as thermoplastic elastomers, with applications such as impact modification, compatibilization and pressure-sensitive adhesion. In solution, their surfactant properties are exploited in foams, oil additives, solubilizers, thickeners and dispersion agents to name a few. Particularly useful reviews of applications of block copolymers in the solid state are contained in the two books edited by Goodman (1982,1985) and the review article by Riess etal. (1985). The applications of block copolymers in solution have been summarized by Schmolka (1991) and Nace (1996). This book is concerned with the physics underlying the practical applications of block copolymers. Both structural and dynamical properties are considered for melts, solids, dilute solutions and concentrated solutions. The book is organized such that each of these states is considered in a separate chapter. 

For formulating poor water-soluble compounds, use of cosolvent(s) is one of the simplest and common approach. The approach is also widely used in the early development phase, as limited information is available for the molecule. The approach also allows overcoming dissolution rate limited drug absorption. In addition, solubilized formulations are greatly popular with pediatric, geriatric, and patients with swallowing difculties. 

Humic macromolecules may not form true micelles, but because they appear to include distinct hydrophobic and hydrophilic regions (Wershaw, 1986), they might be classified as self-micelles. As in the case of completely apolar solutes, the formation of micelles is favored by the reduced volume of water cavity space required to surround the micelle relative to its individual molecules, but in addition, the polar regions of amphiphiles are oriented at the surface of the micelle and provide additional solubilizing capacity through ionic interactions, especially if they are charged. 

Even though chemical structures may dictate the preferred location for the additive, solubilized systems are dynamic, as are the parent micelles, and the location of specific molecules changes rapidly with time. It will always be important to remember that while a given region of the micelle may be preferred by an additive on chemical grounds, there is no guarantee that aU phenomena related to the system (catalysis, for example) will be associated with that region. 

Iodine is not very soluble in water, exhibiting about 300 ppm of water solubility at ambient temperature. Additional solubilizers are used to increase the solubility. The effectiveness of iodine germicides has little dependence on the iodine concentration. It has been reported that the efficacy of iodine teat dips is greatly affected by the concentration of free iodine in the product [91]. Free iodine is a measure of the concentration of uncomplexed or molecular iodine as shown in Equation 10.1 [92] ... 

These reactions are similar to those described earlier, but they contain no additional solubilizing and targeting segments. In fact, this work probably acted as a basis for more elaborate tailoring with respect to the use of carboxylate reactive groups. Other amine-platinum reactants were also described. 

Uses Coactive, detergent, antistat, foam booster/stabilizer and vise, modifier for personal care prods, surgical scrubs, fire fighting foam cones., foamed rubbers, carpet backing, bleach additive solubilizer Properties Pale straw liq. dens. 0.98 g/cc vise. 25 cs (20 C) pH 7.5 0.5 (5% aq.) 30.0 1,5% act,... 

Uses Emollient, spreading agent, penetrant for personal cate prods, incl. bath oils, perfumes, creams/lotions, lipsticks, hair preps., shaving lotions, aerosol toiletries, pharmaceutical ointments solvent carrier for cosmetic additives solubilizer for lanolin... 

Uses Emulsifier and wetting agent for agrochem. powds. and soivs. detergent additive, solubilizer, dispersant emulsifer for creams, lotions solubilizer for topical pharmaceuticals and shampoos... 

Uses Emulsifier, fuel oil additive, solubilizer, degreaser for emulsions Properties Liq. oil-sol. 

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