Alkyl chains alcohols

Czichocki et al. [134] determined the wetting power of several pure and commercial alcohol ether sulfates. The values obtained for pure substances are shown in Table 26. As expected, shorter alkyl chain alcohol ether sulfates are better wetting agents than those having longer alkyl chains. 

In fructose alkylation, van der Heiden et al. have shown that MCM-41 was the catalyst of choice. With short alkyl chain alcohols, quantitative conversions were obtained.[49] In the case of alkyl-fmctosides, 5h of reaction time at reflux of the competent alcohol were required. Only the two kinetically favoured fructofurano-sides were formed. With butanol, the reaction took place at a slightly higher temperature and required a longer reaction time, thus allowing the formation of the jS-D-fructopyranoside isomer besides the two fructofuranosides. 

With long alkyl chain alcohols, the conversion of fructose with 1-octanol to octylfructosides was only 60%, but with 1-decanol and 1-dodecanol the conversion dropped to 40% due to competing of fructose ring opening. However, in 1,2-dimethoxyethane as solvent, a yield in dodecyl-D-fructosides of 60% was obtained after 1.5 h at 83 °C. 

Metal-oxides of the type (Al203)x(Sn0)Y(Zn0)z were also studied as heterogeneous catalysts for the transesterification reaction of soybean oil (Macedo et al., 2006). It was observed that these materials are active for soybean oil alcoholysis with different alkyl-chain alcohols using several alcohols, including branched ones. The best result was achieved using methanol, with conversion yields up to 80% in 4 h. As observed for the complex 1 in homogenous conditions, the catalytic activities are strongly dependent on the nature of the alcohol. For alcohols with a linear chain, the reaction activities decrease with... 

Although they are not micelles, microemulsions and cyclodextrin (CD) derivatives have also been introduced as PSs for MEKC. Oil-in-water (o/w) microemulsions have been shown to be good PSs for EKC. Microemulsions (o/w) are prepared by mixing oil, water, a surfactant, and a cosurfactant such as a medium alkyl-chain alcohol. They have the characteristic properties of a solvent, such as thermodynamic stability and a high solubilization power. The... 

Fig. IV-24. Effect of alkyl chain length of n-alcohols on the resistance of water evaporation at 25°C. (From Ref. 275.)...

Higher alcohols become more hydrocarbon like and less water soluble 1 Octanol for example dissolves to the extent of only 1 mL m 2000 mL of water As the alkyl chain gets longer the hydrophobic effect (Section 2 17) becomes more important to the point that It more than hydrogen bonding governs the solubility of alcohols... 

Environmental Considerations. Environmental problems in Ziegler chemistry alcohol processes are not severe. A small quantity of aluminum alkyl wastes is usually produced and represents the most significant disposal problem. It can be handled by controlled hydrolysis and separate disposal of the aqueous and organic streams. Organic by-products produced in chain growth and hydrolysis can be cleanly burned. Wastewater streams must be monitored for dissolved carbon, such as short-chain alcohols, and treated conventionally when necessary. 

The solubihty of alkylphenols in water falls off precipitously as the number of carbons attached to the ring increases. They are generally soluble in common organic solvents acetone, alcohols, hydrocarbons, toluene. Solubihty in alcohols or heptane follows the generalization that "like dissolves like." The more polar the alkylphenol, the greater its solubihty in alcohols, but not in ahphatic hydrocarbons likewise with cresols and xylenols. The solubihty of an alkylphenol in a hydrocarbon solvent increases as the number of carbon atoms in the alkyl chain increases. High purity para substituted phenols, through Cg, can be obtained by crystallization from heptane. 

Linear ethoxylates are the preferred raw materials for production of ether sulfates used in detergent formulations because of uniformity, high purity, and biodegradabihty. The alkyl chain is usually in the to range having a molar ethylene oxide alcohol ratio of anywhere from 1 1 to 7 1. 

For extraction of uranium from sulfate leach Hquors, alkyl phosphoric acids, alkyl phosphates, and secondary and tertiary alkyl amines are used in an inert diluent such as kerosene. The formation of a third phase is suppressed by addition of modifiers such as long-chain alcohols or neutral phosphate esters. Such compounds also increase the solubihty of the amine salt in the diluent and improve phase separation. 

Alkyl boric acid esters derived from straight-chain alcohols and aryl boric acid esters are stable to relatively high temperatures. Methyl borate is stable to 470°C (11). Trialkoxyboranes from branched-chain alcohols are much less stable, and boranes from tertiary alcohols can even decompose at 100°C (12). Decomposition of branched-chain esters leads to mixtures of olefins, alcohols, and other derivatives. 

Ionic liquids are similar to dipolar, aprotic solvents and short-chain alcohols in their solvent characteristics. These vary with anion (from very ionic Cl to more covalent [BETI] ). IFs become more lipophilic with increasing alkyl substitution, resulting in increasing solubility of hydrocarbons and non-polar organics. 

The Ziegler process produces linear alcohols with an even number of carbon atoms and is based on the polymerization of ethylene under catalytic conditions, generally with triethylaluminum as in the Alfol and the Ethyl processes. The distribution of alkyl chains depends on the version of the process employed but the alcohols obtained after fractionation can be equivalent to those obtained from fats and oils or have purpose-made distributions depending on the fractionation conditions. 

It can be seen that the solubility in water of sodium dodecyl sulfate is around 30%. However, the triethanolamine salt is still more soluble and forms clear solutions at 40% concentration. Figure 3 shows plots of the solubility of sodium alcohol sulfates with alkyl chains from Cn to C18 vs. temperature. As expected, the solubility decreases as the number of carbon atoms in the alkyl chain increases [80]. 

Alcohol sulfates have lower CMCs than sulfonates, which in turn have lower values than carboxylates. It is known that the CMC decreases logarithmically as the number of carbon atoms of the alkyl chain increases, according to Klevens s equation [86] ... 

CMC varies with temperature following a polynomial equation. A general equation relating the CMC of sodium alcohol sulfates to the number of carbon atoms in the alkyl chain and temperature (°C) has been suggested [93] ... 

The foam volume and stability of alcohol sulfates is relatively increased in hard water compared to soft water. The amount and quality of foam is dependent on the alkyl length. Sulfates with C12-C,4 alkyl chains produce the richest creamy foam with small bubbles. C8-C10 alcohol sulfates are foam depressants and C16-C18 alcohol sulfates are poor foaming surfactants. Foams produced by alcohol sulfates are also relatively stable in the presence of sebum. Sodium and ammonium alcohol sulfates foam better than triethanolamine alcohol sulfates. Alcohol ether sulfates produce lighter foams than those of alcohol... 

Sodium dodecylbenzenesulfonate is undoubtedly the anionic surfactant used in the greatest amount because it is the basic component in almost all laundry and dishwashing detergents in powder and liquid forms. However, alcohol and alcohol ether sulfates are the more versatile anionic surfactants because their properties vary, with the alkyl chain, with the number of moles of ethylene oxide added to the base alcohol and with the cation. Consequently, alcohol and alcohol ether sulfates are used in almost all scientific, consumer, and industrial applications. 

The applications of alcohol sulfates in consumer products depend on the alkyl chain and in some cases on the cation. Alcohol sulfates with alkyl chains 8 C1() are seldom used in consumer products except occasionally as hydrotropes in liquid detergent formulations. However, alcohol sulfates in the range C10-C18 are used in many commonly used formulations although other surfactants are generally added to enhance their properties. In some of these applications, particularly in shampoos, they compete with alcohol ether sulfates of the same alkyl chain distribution. The pattern of use of alcohol sulfates or alcohol ether sulfates in formulations varies with consumer personal care and laundry washing preferences in different cultural areas of the world. 

Tallow alcohol sulfate is an important surfactant used in heavy-duty detergents. The unsaturated part of the alkyl chain of tallow alcohol gives their sulfates an improved solubility with excellent detergent and foaming characteristics. 

It is difficult to find an industrial sector that does not use alcohol sulfates or alcohol ether sulfates. These surfactants are rendered so versatile in their chemical structure through varying their alkyl chain distribution, the number of moles of ethylene oxide, or the cation that it is possible to find the adequate sulfate achieving the highest mark in nearly every surfactant property. This and the relative low cost are the two main reasons for their vast industrial use. 

An analysis of alcohol and alcohol ether sulfates should determine the anionic active matter, the unsulfated matter, the inorganic sulfate content, the chloride content, and water. Other more precise analysis must determine the alkyl chain distribution of the alcohol and in the case of alcohol ether sulfates the number of ethoxy groups and its distribution, as well as other more specialized determinations, such as the content of 1,4-dioxane and other impurities. 

The alkyl chain distribution of the base alcohol in alcohol sulfates is easily determined by gas chromatography. However, alcohol sulfates and alcohol ether sulfates are not volatile and require a previous hydrolysis to yield the free alcohol. The extracted free alcohol can be injected directly [306] or converted to its trimethylsilyl derivative before injection [307]. Alternatively, the alcohol sulfate can be decomposed by hydroiodic acid to yield the alkyl iodides of the starting alcohols [308]. A preferred method forms the alkyl iodides after hydrolysis of the alcohol sulfate which are analyzed after further extraction of the free alcohol, thus avoiding the formation of hydrogen sulfide. This latter method is commonly used to determine the alkyl chain distribution of alcohol ether sulfates. 

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