Acid ethoxylates characterization

Sulfonates with ether linkages include ring-sulfonated alkylphenol ethoxylates and a disulfonated alkyldiphenyl oxide, Dowfax 2A1, and 3B2 (Dow Chemical Company). This surfactant is characterized by high solubiUty in salt solutions, strong acids, or bases. It is used in industrial and institutional cleaners. 

In addition to their poor solubility in water, alkyl phosphate esters and dialkyl phosphate esters are further characterized by sensitivity to water hardness [37]. A review of the preparation, properties, and uses of surface-active anionic phosphate esters prepared by the reactions of alcohols or ethoxylates with tetra-phosphoric acid or P4O10 is given in Ref. 3. The surfactant properties of alkyl phosphates have been investigated [18,186-188]. The critical micelle concentration (CMC) of the monoalkyl ester salts is only moderate see Table 6 ... 

Triton SP-Series surfactants use both a hydrophobe and an ethoxylate chain hydrophile. The surfactants are characterized by nonionic surfactant features such as good detergency, surface activity, and wetting. When the pH of an aqueous solution that contains a Triton SP-Series surfactant is reduced, the bond between the surfactant hydrophobe and hydrophile is permanently destroyed, thus eliminating surfactancy. This product was launched commercially in December 1996 and is currently available. The surfactants cannot be used in highly acidic environments. Other compounds that might be found in the contaminated waste, snch as phosphate, may interfere with the oil/water separation after snrfactant deactivation. All information is from the vendor and has not been independently verified. 

It is only a small step from the alkyl sulfates to the so-called alkyl ether sulfates. These surface-active agents are made from alcohols which are ethoxylated. The formed fatty alcohol polyglycol ethers possess a final OH-group which then reacts with sulfuric acid. Fatty alcohol polyglycol sulfates are characterized by an insensitivity to water hardness and low irritation of the skin. Their aqueous solutions can be easily thickened by the addition of sodium chloride. These properties thus attract attention for the use of fatty alcohol polyglycol sulfates in cosmetic products. 

Ethoxylated amine Ethoxylated ester Alkyl/EO ratio Characterization of acid Other tests... 

During the synthesis of ethoxylated polymers, chain termination can occur by a mechanism which results in the formation of a RC=CH2 group, rather than the desired terminal hydroxyl group. These compounds typically have a lower average molecular weight than the main component. Unsaturation determination is also required when characterizing other compounds, especially those made from natural fatty acids. In this case, the double bonds are usually not terminal but internal. 

Anyone seeking to characterize ethoxylated acids should study the specifications and descriptions of the fatty acid starting materials, for which excellent brochures are available from major suppliers. For example, the oleic acid of commerce is a mixture of carboxyhc acids but also contains other materials, which can total several percent. The purchaser has a choice of several grades of this so-called oleic acid, with the pharmaceutical grades not necessarily being the purest. Consider the fate of the impurities during the ethoxylation reaction to predict what might be likely impurities in the final product. 

The determination of active agent is complicated by the presence of various impurities in the commercial product ethoxylated ethanolamine, ethoxylated ester, polyethylene glycol, fatty acid. The nonaqueous titration is rapid, but requires knowledge of the equivalent weight of the surfactant. This makes the method unsuitable for the analysis of unknown materials unless further characterization is performed. 

GC methods are summarized in Tables 2 and 3. Sulfates of alcohols and ethoxylated alcohols are readily decomposed by acid hydrolysis to yield the free alcohols or ethoxylated alcohols. The trimethylsilyl derivatives of these are easily analyzed by gas chromatography (24). Derivatization of the alcohols may be omitted if they have reasonable volatility (25). Alternatively, the surfactant may be decomposed by hydriodic acid, giving alkyl iodide derivatives of the starting alcohols for characterization by gas chromatography (26). Hydrolysis can be combined in the same step with derivatization. Reaction of alkyl sulfates with silylating agents such as BSTFA/1% TMCS results in cleavage of the sulfate and formation of the trimethylsilyl ethers of the alcohols (27). GC or GC-MS analysis will... 

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