Ethoxylate number

Aliphatic AEOs, considered as environmentally safe surfactants, are the most extensively used non-ionic surfactants. The commercial mixtures consist of homologues with an even number of carbon atoms ranging typically from 12 to 18 or of a mixture of even-odd linear and a-substituted alkyl chains with 11—15 carbons. Furthermore, each homologue shows an ethoxymer distribution accounting typically for 1—30 ethoxy units with an average ethoxylation number in the range 5—15. The separation of the AEO complex mixtures was achieved by reversed-phase and normal-phase chromatographic systems [74—76]. 

Commercial alkylphenol ethoxylates come with almost 100 % surfactant content or with rheological modifiers. Their consistency changes from liquid via paste to solid wax as ethoxylation number rises. Isooctylphenol and isononylphenol ethoxylates with m <4 are oil-soluble, those with m = 4-5 form emulsions in water, and products with m > 5 form clear aqueous solution. 

The temperature interval in which a central microemulsion region exists is shifted to higher temperatures by increasing the mean ethoxylation number of the C 2-i4 all l polyglycol ether, and to lower temperatures by the addition of /i-pentanol. The variation of the ethoxylation number and a defined addition of n-pentanol are thus tools to prepare bicontinuous microemulsions at a given washing temperature. 

The principles established in the preceding two sections can now be applied to identifying an unknown surfactant. The example of Figure 11.4 will be used here as the unknown, simply because the information obtained from this exercise will be applied later (section 11.6) to gain quantitative information about alkyl chain length and ethoxylate number for this anionic surfactant. 

The above chemical shift assignments and integrations also allow us to determine the average ethoxylate number for this surfactant. Given that the ethoxylate peak ( c ) is at 3.7 ppm ... 

Problem 7.12 Adsorption of nonyl-phenyl-ethoxy-lates on two different polymer surfaces The figure below shows the adsorption of three nonyl-phenyl-ethoxylates (non-ionic surfactants) with different ethoxylate numbers at two polymer surfaces (PMMA and PS). The polarity of the two poljmiers is 0.3 (PMMA) and 0.2 (PS), expressed on a relative polarity scale. The arrows indicate the CMC values. 

These detergent range (C C ) odd and even linear internal olefins are fed to oxo-alcohol plants to produce C22 C2 semilinear alcohols. Most of the alcohols are ethoxylated and sold into detergent markets (8). Shell balances carbon numbers by a combination of the ethylene oligomerization extent. 

The number of ethylene oxide units added to the phenoxide depends on the apphcation of the ethoxylate. This chemistry is closely related to the reaction between an alkylphenol and epichlorohyddn which is used ia epoxy resias (qv). 

The stmctural architecture of siUcone polymers, such as the number of D, T, and Q sites and the number and type of cross-link sites, can be deterrnined by a degradative analysis technique in which the polymer is allowed to react with a large excess of a capping agent, such as hexamethyidisiloxane, in the presence of a suitable equiUbration catalyst (eq. 38). Triflic acid is often used as a catalyst because it promotes the depolymerization process at ambient temperature (444). A related process employs the KOH- or KOC2H -catalyzed reaction of siUcones with excess Si(OC2H )4 (eq. 39) to produce ethoxylated methylsiUcon species, which are quantitatively deterrnined by gc (445). 

Average number of ethoxyl groups per glucose unit Solubility... 

The composite results of benzo-fusion on the rates and activation energies of ethoxylation and of piperidination are summarized in round numbers in Scheme VI to give a broad perspective. 

Alcohols obtained from fats and oils contain an even number of carbon atoms and they are completely linear. Alcohols obtained from petrochemical sources can be linear or branched, depending on the manufacturing process, and can also have even or odd numbers of carbon atoms. In many practical applications the small differences observed in the behavior of sulfated alcohols or indeed sulfated alcohol ethoxylates from either source is of no significance and the choice is made on economic grounds. 

Alcohols react with nascent hydroiodic acid to form alkyl iodides. When the starting material is an alcohol ether sulfate, the resulting alcohol ethoxylate obtained by acid hydrolysis of the sulfate gives the corresponding alkyl iodides. The number of moles of diiodoethane equals the number of moles of ethylene oxide present in the alcohol ethoxylate. Diiodoethane decomposes or reacts with more hydrogen iodide to give iodine quantitatively in both cases. However,... 

A great number of nonionic surfactants have been ethoxylated and subsequently reacted with P4O10. The acid phosphate esters from this reaction possess surface properties and detergency similar to the nonionic surface-active agents employed as reactants. Detergency tests and foam heights from the Ross-Miles method have been reported for a series of compounds. Various formulations for all-purpose cleaners are given as well [37,40,41,44,48]. 

There is no molecular interaction between nonionic surfactants with an ethylene-oxide chain, i.e. Genapol and ethoxylated nonylphenols. Indeed, research by Nishikido (6) on polyoxyethylene laurylethers (5 < E.O. number < 49) has shown the ideal behavior (p12 = 0) of their mixtures. Likewise, Xia (7) has found very low p12 values for mixtures of ethoxylated fatty alcohols. 

Two different instrumental measurements were used to test the oxidation hypothesis GC and atomic absorption (AA). GC was used to determine the chain length distribution of the EO. From the GC results, an average chain length number was calculated. The gas chromatogram is shown in Fig. 21.1. In addition, headspace GC measurement of the gaseous compounds dissolved in the liquid ethoxylate was made and compared to typical or good product. Atomic absorption spectroscopy was used to determine the levels of several trace metals known to catalyze oxidation of fatty chemicals. 

This is a very important group of products and most of them are adducts of long-chain alcohols or alkylphenols with a number of ethylene oxide (EO) units. Adducts with propylene oxide (PO) and copolymers of ethylene and PO are also used although they are less important in terms of usage volume than the pure ethoxylate derivatives. 

The most representative non-ionic surfactants are the alkyl (alcohol) ethoxylates. These are adducts of a long-chain alcohol (12—18) with a variable number of EO units (3-11). Other non-ionic surfactants are derived from carbohydrates (glucoside and glucamide derivatives), organosilicones, fatty alcohols, and amides. Products in this category are as follows (compare also Table 1.2) ... 

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