Nonionic Emulsifying

Collone NI Crodex N Emulgade lOOONI Permulgin D Polawax Ritachol 2000 T-Wax. 

Nonionic emulsifying wax is used as an emulsifying agent in the production of oil-in-water emulsions that are unaffected by moderate concentrations of electrolytes and are stable over a wide pH range. The concentration of wax used alters the consistency of a product owing to its self-bodying action at concentrations up to about 5% a product is pourable. 

Concentrations of about 15% of nonionic emulsifying wax are commonly used in creams, but concentrations as high as 25% may be employed, e.g., in chlorhexidine cream BP. Nonionic emulsifying wax is particularly recommended for use with salts of polyvalent metals and medicaments based on nitrogenous compounds. Creams are susceptible to microbial spoilage and should be adequately preserved. 

Nonionic emulsifying wax is also used in nonaqueous ointment bases, such as cetomacrogol emulsifying ointment BP, and in barrier creams. 

Nonionic emulsifying wax is a white or off-white waxy solid or flakes which melt when heated to give a clear, almost colorless liquid. Nonionic emulsifying wax has a faint odor characteristic of cetostearyl alcohol. 

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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. 

Formation of Hposomal vesicles under controlled conditions of emulsification of Hpids with phosphoHpids has achieved prominence in the development of dmgs and cosmetics (42). Such vesicles are formed not only by phosphoHpids but also by certain nonionic emulsifying agents. Formation is further enhanced by use of specialized agitation equipment known as microfluidizers. The almost spontaneous formation of Hposomal vesicles arises from the self-assembly concepts of surfactant molecules (43). Vesicles of this type are unusual sustained-release disperse systems that have been widely promoted in the dmg and cosmetic industries. 

Clear solutions of antiperspHants have been on the market for about 100 years. Cream and lotion types are o/w emulsions commonly formulated using nonionic emulsifiers to avoid aluminum salt formation, especially by carboxyHc acids. Cream antiperspHants are generally distributed in jars, whereas lotions are dispensed from roU-on types of containers. 

Fig. 11. In a system of water and hydrocarbon a nonionic emulsifier with a poly(ethylene glycol) chain as the polar part dissolves in the aqueous phase at low temperatures (a) and in the oil phase at high temperatures (c). At an intermediate temperature (b) three isotropic Hquid phases may be found.

Medvedev et al. [57] extensively studied the use of nonionic emulsifiers in emulsion polymerization. The emulsion polymerizations in the presence of nonionic emulsifiers exhibited some differences relative to those carried out with the ionic ones. Medvedev et al, [57] proposed that the size of latex particles remained constant during the reaction period, but their number increased continually with the increasing monomer conversion. The use of nonionic emulsifiers in emulsion polymerization usually results in larger sizes relative to those obtained by the ionic emulsifiers. It is possible to reach a final size value of 250 nm by the use of nonionic emulsifiers in the emulsion polymerization of styrene [58]. 

Spernath, A. et al.. Food-grade microemnlsions based on nonionic emulsifiers media to enhance lycopene solubilization, J. Agric. Food Chem., 50, 6917, 2002. 

The determination of adsorption isotherms at liquid-solid interfaces involves a mass balance on the amount of polymer added to the dispersion, which requires the separation of the liquid phase from the particle phase. Centrifugation is often used for this separation, under the assumption that the adsorption-desorption equilibrium does not change during this process. Serum replacement (6) allows the separation of the liquid phase without assumptions as to the configuration of the adsorbed polymer molecules. This method has been used to determine the adsorption isotherms of anionic and nonionic emulsifiers on various types of latex particles (7,8). This paper describes the adsorption of fully and partially hydrolyzed PVA on different-size PS latex particles. PS latex was chosen over polyvinyl acetate (PVAc) latex because of its well-characterized surface PVAc latexes will be studied later. 

Dursban 2E Emulsifiable concentrate of 0.285 kg/L (2.4 Ib/gal) Solution in aromatic distillate with anionic/nonionic emulsifier blend and residual chlorinated solvent... 

Nonintentional food additives, 12 29 Noninteracting solvents, 23 99 Nonionic emulsifiers, in VDC emulsion polymerization, 25 722-723 Nonionic functional groups, in polymer colloids, 20 384... 

In this study, mechanical properties of emulsion copolymers of viityl acetate and butyl aciylate, which consisted of a nonionic emulsifier (30 mol ethoxylated nottyl-phenol), an oligomeric stabilizator, and ammonium persulfate or potassium persulfate as initiators by changing monomer ratios from 90 10 to 10 90 for VAc BuA, were determined by differential scanning calorimeter. 

Systems and materials. The reaction was carried out at several compositions in an ionic and in a nonionic system. The ionic system consisted of an emulsifier (49.6 wt % cetyltrimethyl ammonium bromide (CTAB)/50.4% n-butanol), hexadecane, and water. The nonionic emulsifier consisted of 65.7% polyoxyethylene (10) oleyl ether (Brij 96) and 34.4% n-butanol, again with hexadecane and water. In both systems, mlcroemulslon (pE) compositions used were obtained by diluting an initial 90 weight percent (%) emulsifler/10% oil mixture with varying amounts of water. Micro-emulsion samples thus obtained had final compositions of 30 to 80% water. Phase maps describing these systems have been published (10-11). 

K. Shinoda and H. Aral The Correlation between Phase Inversion Temperature in Emulsion and Cloud Point in Solution of Nonionic Emulsifier. J. Phys. Chem. 68,... 

A similar effect was noted in separate investigations by another group [108], Oil-in-water HIPEs, where the oil phase contained aromatic or halogenated liquids, were difficult or impossible to form, with nonionic surfactants. This was postulated to be as a result of interactions between the polar ethylene oxide groups of the surfactant and the aromatic or halogenated solvents, which are more polar than hydrocarbons. Water-in-oil systems also displayed this tendency [21] however, w/o HIPEs with m-xylene as the oil phase [13] could be produced with monolaurin as nonionic emulsifier, due to stronger intermolecu-lar interactions at the interface. 

Examples of nonionic emulsifiers are polyoxyethylene, polyoxypropylene, fatty alcohol ether, polyethylene (or polypropylene), glycol fatty acid esters, lecithin, lanolin, cholesterol, etc... 

CondChemDict (1961), p 438 (Emulphors are nonionic emulsifying dispersing agents the compn of Emulphor CO-10 is not reported)... 

Figure 6. General features of the isotropic solution regions in a system water, hydrocarbon, and nonionic emulsifier with an oxyethyl-ene chain length of about 4. The numbers 1-6 show the regions at increasing temperatures.

Regions containing a liquid crystalline phase in systems comprised of water, a hydrocarbon, and a nonionic emulsifier (polyoxyethylene... 

An important group of surface-active nonionic synthetic polymers (nonionic emulsifiers) are ethylene oxide (block) (co)polymers. They have been widely researched and some interesting results on their behavior in water have been obtained [33]. Amphiphilic PEO copolymers are currently of interest in such applications as polymer emulsifiers, rheology modifiers, drug carriers, polymer blend compatibilizers, and phase transfer catalysts. Examples are block copolymers of EO and styrene, graft or block copolymers with PEO branches anchored to a hydrophilic backbone, and star-shaped macromolecules with PEO arms attached to a hydrophobic core. One of the most interesting findings is that some block micelle systems in fact exists in two populations, i.e., a bimodal size distribution. 

With nonionic PEO emulsifiers, intermolecular interactions vary with temperature and types of metal ions and solvents. At low temperatures, nonionic emulsifiers are hydrophilic and form normal micelles. At higher temperatures they are lipophilic and form reverse micelles. A weak interaction with metal ions favors the stability of associates against moisture. On the other hand, a strong interaction may lead to a completely amorphous system. Ethanol as a co-solvent is a moderate solvent for PEO at low temperatures, but its power improves as the temperature is raised [34]. This means that solutions of the PEO copolymers in water and ethanol have opposing temperature coefficients of solubility negative for water and positive for ethanol. 

The water solubility of R-(EO)n types of nonionic emulsifiers is derived from the weak interaction between the ether oxygen of EO unit and water. It was suggested that each EO unit in the PEO chain, requires three molecules of water to form a hydrated complex [35]. This hydrogen bond complex is destroyed if the solution is taken above the melting point of the PEO. Water usually acts as plasticizer when present in hydrophilic PEO polymers and Tg values decrease with increasing water contents [36]. This phenomenon in the PEO-water system is observed up to 1 mol water/ether group. Beyond this a rise in Tg is observed and water acts as an antiplasticizer. 

Ten years later Napper and Alexander, in studying the kinetics of vinyl acetate polymerization in the presence of anionic, cationic and nonionic emulsifiers arrived at the same conclusions as Priest s, although they did not cite his work (13). They also observed an acceleratory effect of added emulsifier like that found by Baxendale et al. (8), but they seemed unaware of that work as well. They showed that when the charge on primary particles (due to initiator fragments) was opposite to that of the emulsifier, the rate of polymerization was slower than that in the absence of emulsifier. This was presumably due to the greater instability of the colloid formed and the consequent production of fewer polymerizing centers. 

The latex was cleaned by ion exchange and serum replacement, which gave the cleaned latex plus six serum fractions. The cleaned latex and the serum samples were analyzed by conductometric titration. Also, the amount of anionic emulsifier in the serum was determined by Fyamine 1622 colorimetric titration and thin-film chromatography, and the amount of nonionic emulsifier by iodine-iodide colorimetric titration and thin-film chromatography. 

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