Nonylphenol ethoxylates derivatives

APEOs are used in domestic and industrial applications. They are applied as detergents, emulsifiers, wetting agents, dispersants or solubilisers. APEO derived from nonylphenol (NP), i.e. nonylphenol ethoxylates (NPEOs) comprises about 80% of the total market volume, while octylphenol-derived surfactants (OPEOs) account for 15-20%. Because of the persistence and toxicity of some degradation intermediates, their use has been reduced in several countries either through voluntary bans by the chemical industry or by legal regulations. However, excellent properties in combination with comparably low production costs hampers their complete replacement with other more environmentally acceptable alternatives. 

Octyl- and nonylphenol are well known raw materials used in the surfactant industry since the early 1960s, mainly for the production of their corresponding ethoxylated derivatives (APE). Today, these products have lost considerable importance in this industry as a consequence of substantial environmental threats, resulting from their relatively slow biodegradation, toxicity of their biodegradation metabolites and positive endocrine-disrupting reactions. 

Wastewater-derived alkylphenolic compounds have been studied extensively. The concentrations of nonylphenol ethoxylates (NPEOs), as the strongly prevalent sub-group of APEOs, determined in the influents of WWTPs (Table 6.1.4), varied widely among various WWTPs from <30 to 1035 pg L 1. However, values can go up to 22 500 pg L-1 in industrial wastewaters (especially from tannery, textile, pulp and paper industry). Levels of octylphenol ethoxylates (OPEOs) are significantly lower, comprising approximately 5-15% of total APEOs in WWTP influents, which is congruent with their lower commercial use. 

Canada [8]. In this document all three approaches have been performed after an extensive literature study of effects documented and environmental concentrations measured in the Canadian aquatic environment. Thus, based on the most sensitive endpoint found in the literature (LC50 of nonylphenol (NP) for winter flounder 17 pig L-1 [9]), and applying an uncertainty factor of 100, for NP a PNEC of 0.17 p.g L-1 was derived. Analogously, NEC were derived for nonylphenol ethoxylates (NPEO) and nonylphenol ethoxy carboxylates (NPEC) these are listed in Table 7.4.1. 

Atlox 3470, a product of ICI Ltd. is classed as an anionic/ non-ionic surfactant comprised mainly of dodecyl benzene sulfonate (anionic) and a nonylphenol ethoxylate of polyethylene glycol (non-ionic emulsifyer). Recent evidence strongly suggests that the active agent in the viral enhancement coincident with Reye s syndrome is a polyethylene glycol derived from the polyethylene moiety of the parent emulsifyer when the number of repeating ethoxy units in the polymer approaches 9 or 10 (12). 

In recent years considerable attention has been given to the biodegradability of polyethoxylates and the role of their structure in this process. In consequence, there has been a move away from multi-branched alkyl side-chain in the starting alkylphenolic raw material towards more linear chains, a circumstance already adopted in the use of kerylbenzenes for the manufacture of alkylaryl sulphonates. Another practice adopted has been that of sulphation of the terminal hydroxyl group in the polyalkoxylate. Recent studies on a comparison of ethoxylates derived from the natural alkenylphenol, cardanol and from nonylphenol have indicated a considerable difference in biodegradability (ref. 24). 

Sodium anacardate is an excellent soap the water solubility of which has been used in a subsequent reaction (ref. 283). There has been, following work on the preparation of cardanol polyethoxylate (ref.284,285,286), by the reaction of cardanol with ethylene oxide at 180 C in the presence of a catalytic amount of potassium hydroxide, considerable interest in its ready biodegradability compared with that of ethoxylates derived from t-nonylphenol (ref.287). The individual ethoxy late oligomers were synthesised having values of n = 1 to 6 to identify the oligomers present in cardanol polyethoxylate and the ready biodegradation of cardanol and to a lesser extent that of of cardol polyethoxylates quantitatively established in comparison with that of t-nonylphenol polyethoxylate which remain comparatively undegraded. 

Alkylated phenol. The most commonly used alkylated phenol ethoxylates (APE) have included octyl phenol ethoxylate and nonylphenol ethoxylates with 3-11 moles of EO, which were produced by alkylation of butylene dimer or propylene trimer onto phenol and subsequent ethoxylation. They had been used extensively in laundry and hard surfacecleaning applications in the nonionic form, and as the sulfated and phosphated derivatives of the low-mole ethoxylates in a variety of industrial applications. Concerns over the environmental impact of the partial metabolites generated during the waste treatment of these surfactants has prompted their elimination from European consumer product formulations, and their deformulation from most consumer products in North America and elsewhere in the world. 

Excellent selectivity for APE is provided by fluorescence detection. Quantification in reversed-phase mode requires only the measurement of the single peak for nonylphenol ethoxylates (octylphenol derivatives are rarely found), while normal phase chromatography permits determination of the homolog distribution (104,106). For even more selective fluorescence detection of APE, the analysis may be made with and without acetylation. Many impurities lose their fluorescence after acetylation. The change in retention time of the acetylated compounds confirms the identity of the APE peaks (93). Fluorescence detection is much more sensitive than UV detection for nonylphenol (105). 

They are now being replaced by the polyoxyethylene derivative of straight-chain primary or secondary alcohols with C10-C18. These linear alcohol ethoxylate nonionic surfactants are more biodegradable than nonylphenol derivatives and have better detergent properties than linear alkylbenzenesulfonate. 

There are over 150 different producers and some 2 million tonnes of commercial nonionic surfactants manufactured worldwide of which at least 50% are alkoxylated alcohols. Ethoxylated nonylphenol production is falling and accounts for 20% of the market while alkoxylated fatty acids account for some 15%. Fatty acid amides and sugar esters account for another 10% and there are a large number of specialities making up the balance. In general, non-ionic surfactants are easy to make, relatively inexpensive and derived from a variety of feedstocks. 

These were probably the first ethoxylates produced in large quantities and were important from the mid- 1940s. They were largely based on nonylphenol with much smaller quantities of octyl and dodecylphenol derivatives. The first mole of ethylene oxide adds with relative ease to the alkyl phenol and then additional moles of ethylene oxide add to produce a Poisson distribution certainly up to the 10-mol derivative [8, 9]. 

Derivatives of nonylphenol up to about the 12-mol ethoxylate are liquid at ambient temperature and do not require heated storage. They are used for reducing oil-water interfacial tension and are excellent for removing oily soils. The major drawback is the biodegradation resistance of the benzene ring, which limits the use to industrial applications in which waste can be treated before any discharge to waterways. However, their relative cheapness has maintained their use in some formulations destined for the household market in certain parts of the world. 

Nonionic miniemulsions can be made by using 3-5% of a polyfethylene oxide) derivative as surfactant, resulting in larger, but also very well defined latexes [51]. Chern and Liou used a nonionic surfactant nonylphenol poly-ethoxylate with an average of 40 ethylene oxide units per molecule [53]. Particle sizes between 135 and 280 nm were realized. The particle size mainly depends on the type and amount of the hydrophobe and therefore on the degree of the suppression of Ostwald ripening [53]. 

The ohgomeric distribution of NPEO depends on the enviromnental compartment. In this respect, the dissolved phase of waters (seawater and wastewaters) contain higher ethoxamers, whereas river and marine sediments oidy contain nonylphenol and the lower oligomer derivatives (Fignre 4). Nonylphenol and its low-ethoxylated components have been identified in mechanical-biological sewage treated and in some biodegradation experiments", so that its preferential occurrence in the sediment may be due to these effects and/or to their preferent association to the particnlate material. 

Alkylphenol ethoxylates, still mainly derived from branched nonylphenol, now have only modest uses. 

The most widely used alkylphenols in the manufacture of nonionic surfactants are described as follows in the order of their importance. APEs derived from p-nonylphenol account approximately 80% of the total market whereas those derived from octyl phenol account for 15-20%. Dodecyl phenol, di-nonylphenol, and DSBP ethoxylates run a poor third at <5%. 

Low-viscosity concentrates (-10% to 20%) of fabric softeners such as imidazoline derivatives and other diaUcyl ammonium compounds have been prepared by making use of high-pressure homogenization [15] fatty alcohols, aliphatic fatty acids, and fatty acid methyl esters [16] paraffin oils and paraffin waxes [17] ionogenic and nonionogenic emulsifiers (such as ethoxylated nonylphenol... 

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