Higher alcohols alcohol ethoxylates

It has been claimed that complexes of P-cyclodextrin with anionic surfactants, notably higher fatty alcohol ethoxylates, improve scouring efficiency on cotton and wool in laboratory-scale processing [34]. Residual surfactants carried over from preparation can have undesirable effects in subsequent processing. When cyclodextrins complex with surfactants, their surface activity is reduced. Hence cyclodextrins are potentially useful for the removal of residual amounts of surfactants from substrates [35]. The use of a- and P-cyclodextrins has been studied in this context with one cationic, one anionic and four... 

Another preservative used in the analysis of non-ionic surfactants is sodium azide (NaNs), normally used at a concentration of 100 mg L-1. Kiewiet et al. [11] tested much higher concentrations and found that 0.01 M (650 mg LT1) sodium azide could not prevent substantial losses of the alcohol ethoxylates, probably due to the fact that sodium azide is only an inhibitor for aerobic degradation. However, in closed bottles, anaerobic degradation processes could play an important role as well. They observed substantial losses (17-81%) of non-ionic surfactants during transport and seven days storage of the wastewater samples. 

A mixture of nonionic surfactants, consisting of a capped alkylphenol ethoxylate or an ethoxylated higher aliphatic alcohol... 

Polyalkoxycarboxylales surfaclanls are produced either by Ibe reaction of sodium chloroacetate with an alcohol ethoxylate or from an acrylic ester and an alcohol alkoxylatc. Because of the presence of the ethylene oxide linkages, these products possess a higher aqueous solubility which manifests itself in greater compatibility with cationic surfactants and polyvalent cations. 

Melting point (TM) data exist for a number of surfactants. Table 17.6 gives a compilation of Tm data. Values of TM of the linear alcohol ethoxylates range between 289 and 321 K. They increase with increasing length of the alkyl chain as well as the ethoxylate moiety. The values for the ionic surfactants are higher. Table 17.6 shows that the counterion is of influence on the I m of the salt. 

Vapor pressure data are not available for the ionic and nonionic surfactants. Some alcohol ethoxylates have been analyzed by high temperature gas chromatography, but the fact that elution temperatures of the higher ethoxylated AEs are above 520 K on a SE 30 boiling point column (Stancher and Favretto, 1978) indicates that the vapor pressure of these compounds is comparatively low. This is consistent with the high boiling points of these compounds. In addition, since surfactants are rather water soluble, their Henry s law constants can be expected to be very low. Actually, no measured Henry s law constants are available. As a result, evaporation of surfactants can be expected to be negligible. 

The major derivatives of normal primary higher alcohols used in the detergent industry were discussed. These included alcohol ethoxylates, alcohol ether sulfates, and alkyl sulfates. The chemical reactions for preparation of each were also given. 

The third plant for higher secondary alcohols was constructed by Nippon Shokubai in Japan in 1972. The plant capacity, originally 12,000 tons per year of 3 mole ethoxylate, was expanded to 18,000 tons per year in 1977 and now is being further expanded to 30,000 tons per year. Nippon Shokubai s products are also sold mainly in the form of ethoxylate under the registered trade name of SOFTANOL. The alkyl carbon range of SOFTANOL is from 12 to 14 so far. 

Chemistry and general properties. The chemistry of ether sulphates is very similar to that of alkyl sulphates. The backbone of the molecule is a fatty alcohol and often the same alcohols are used as feedstocks for alkyl sulphates, and alkyl ether sulphates and, with higher degrees of ethoxylation, as non-ionic surfactants. The ethoxylation process is more fully described in Chapter 5. 

Ether sulphates show a strong salt effect - that is an increase in viscosity on addition of salt (or other electrolyte). The response to electrolyte (the salt curve ) can be very different between ether sulphates, even from different suppliers of the same product. Generally, the more soluble the surfactant, the lower the salt response but higher degrees of ethoxylation reduce salt response, as does branching in the alcohol as shown in Figure 4.20. 

Linear internal monoolefins can be oxidized to linear secondary alcohols. The alpha (terminal) olefins from ethylene oligomerization, described earlier in this chapter, can be converted by oxo chemistry to alcohols having one more carbon atom. The higher alcohols from each of these sources are used for preparation of biodegradable, synthetic detergents. The alcohols provide the hydrophobic hydrocarbon group and are linked to a polar, hydrophilic group by ethoxylation, sulfation, phosphorylation, and so forth. 

EO/mole of parent alcohol and then gradually declined. Somewhat different behavior was observed using supercritical COj-extracted stock tank oil which had a higher carbon number 26 vs 16), a higher asphaltene content (1.52% vs 0.78%), and a higher combined acid and base number (0.85% vs 0.33) than the unextracted oil (see above). The maximum foam volume was observed at a lower ethylene oxide content (for 15 20 moles of EO vs 30 moles of EO for unextracted oil). The decline in foam volume with further increases in EO content was much more rapid in the presence of COj-extracted oil. This behavior was also observed for 5 alcohol ethoxyl-ates and Cg alcohol ethoxylates. 

Foam exhibits higher apparent viscosity and lower mobility within permeable media than do its separate constituents.(1-3) This lower mobility can be attained by the presence of less than 0.1% surfactant in the aqueous fluid being injected.(4) The foaming properties of surfactants and other properties relevant to surfactant performance in enhanced oil recovery (EOR) processes are dependent upon surfactant chemical structure. Alcohol ethoxylates and alcohol ethoxylate derivatives were chosen to study techniques of relating surfactant performance parameters to chemical structure. These classes of surfactants have been evaluated as mobility control agents in laboratory studies (see references 5 and 6 and references therein). One member of this class of surfactants has been used in three field trials.(7-9) These particular surfactants have well defined structures and chemical structure variables can be assigned numerical values. Commercial products can be manufactured in relatively high purity. 

A low EO addition rate (in fact a low ethoxylation pressure), leads to perfectly clear capped polyols, because the alcohol - alcoholate equilibrium has enough time to get established and, as an immediate consequence, the same quantity of EO is distributed on a high number of hydroxyl groups. Shorter poly[EO] chains derived from a high number of hydroxyl groups are formed and the primary hydroxyl content is higher. To conclude, in order to obtain a high primary hydroxyl content, the rate of EO addition has to be low [51]. For example, for a polyol of MW of 4700-5000 daltons and 15% EO as terminal block, an addition of EO in around three-five hours at 130 °C is a convenient way to obtain a primary hydroxyl content of 70-75%. 

One observes that with temperature increase, the ratio between the reaction rate of EO with the primary hydroxyl, as per the reaction rate of EO with secondary hydroxyl, decreases. If at 70 °C, EO is three times more reactive in the reaction with the primary hydroxyl than with the secondary hydroxyl at 120 °C, EO is only 1.6 times more reactive in the reaction with the primary hydroxyl than in the reaction with the secondary hydroxyl. As an immediate consequence, by ethoxylation of propoxylated polyethers at higher temperatures (125-130 °C), a more uniform distribution of EO units per hydroxyl group takes place and the resulting primary hydroxyl content is higher than that resulting from ethoxylation at lower temperatures (90-105 °C). Of course, another beneficial effect of a higher ethoxylation temperature is that the equilibrium of alcohol - alcoholate is established more rapidly. 

Alcohols are hydrocarbon derivatives with hydroxy groups. Primary long-chain C o-Cig alcohols are the most interesting compounds as surfactants. They exhibit all the properties of nonionics with the exception of micelle formation in aqueous solution. Higher aliphatic alcohols are better soluble in oils than in water. They are widely used as co-surfactants/ emulsifiers and foam stabilizers in aqueous solutions of anionic surfactants. Furthermore, alcohols serve as an intermediate raw material in manufacturing water-soluble surfactants, such as ethoxylated products and ether sulphates [7-11]. 

The salts of monoesters of sulphuric acid (mainly known as alkyl sulphates, alcohol sulphates or sulphated higher alcohols and ether sulphates or sulphated ethoxylated alcohols) have been proceeded for tens of years through the competition with alkylbenzenesulphonates and other anionic and nonionic surfactants with respect to the consumer s merits and cost performance. Among other surfactants, the today s world consumption share of alcohol sulphates and ether sulphates is ca. 25 % in household and laundry aids and ca. 20 % in personal care products [81]. The formers are mostly based on sulphates of petrochemical origin whereas the least are more oriented to sulphates from oleochemicals. 

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