Octylphenol ethoxylates

Many different types of foaming agents are used, but nonionic surfactants are the most common, eg, ethoxylated fatty alcohols, fatty acid alkanolamides, fatty amine oxides, nonylphenol ethoxylates, and octylphenol ethoxylates, to name a few (see Alkylphenols). Anionic surfactants can be used, but with caution, due to potential complexing with cationic polymers commonly used in mousses. 

Gilsonite is active as a fluid loss additive because the permeability of cement is reduced. Latex additives also act as fluid loss additives. They also act as bonding aids, gas migration preventers, and matrix intensifiers. They improve the elasticity of the cement and the resistance to corrosive fluids [921]. A styrene-butadiene latex in combination with nonionic and anionic surfactants shows less fluid loss. The styrene-butadiene latex is added in an amount up to 30% by weight of the dry cement. The ratio of styrene to butadiene in the latex is typically 2 1. In addition, a nonionic surfactant (octylphenol ethoxylate and polyethylene oxide) or an anionic surfactant, a copolymer of maleic anhydride, and 2-hydroxypropyl acrylate [719] can be added in amounts up to 2%. 

FIGURE 18.2 Capillary gel electrophoresis separation of an octylphenol ethoxylate sulfate (with an ethylene oxide chain length from 1 to 8). Run conditions pH 8.3 (100 mM tris-borate, 7 M urea) 50 pm x 75 cm J W polyacrylamide gel capillary (PAGE-5, 5%T, and 5%C) run at 20 kV with a 5kV injection for 5 s UV detection at 260nm. 

Surfactants are separated according to adsorption or partitioning differences with a polar stationary phase in NPLC. This retention of the polar surfactant moiety allows for the separation of the ethylene oxide distribution. Of all the NPLC packings that have been utilized to separate nonionic surfactants, the aminopropyl-bonded stationary phases have been shown to give the best resolution (Jandera et al., 1990). The separation of the octylphenol ethoxylate oligomers on an amino silica column is shown in Fig. 18.4. Similar to the capabilities of CE for ionic surfactants, the ethylene oxide distribution can be quantitatively determined by NPLC if identity and response factors for each oligomer are known. 

Similar results were previously seen with a similar column and a gradient (Ibrahim and Wheals, 1996). Although PEG was not analyzed in this work, nonylphenol ethoxylates eluted after octylphenol ethoxylates, suggesting an alkyl contribution to retention. Since AE s have both a hydrophobic and a hydrophilic section, the alkyl portion may be interacting with the hydrophobic siloxane functionality and the EO portion may be interacting with the hydrophilic silanol functionality of the silica. 

Fig. 2.2.5. Migration behaviour of octylphenol ethoxylates with dependence on degree of ethoxylation. Buffer 10 mmol LT1 phosphate, pH 6.8, 70 mmol L-1 SDS, 35% acetonitrile. Samples Igepal CA-520 (n — 5) Triton X-100 (n — 9-10) Igepal CA-720 (n — 12) Triton X-405 (n = 40). Reprinted with permission from Ref. [22] 1997 Springer Verlag.

In one study, however, atmospheric pressure chemical ionisation (APCI)-MS was applied for the simultaneous determination of LAS and octylphenol ethoxylates (OPEO) in surface waters after preconcentration by solid-phase extraction (SPE) on Cis cartridges [1]. In the chromatogram from a Ci-reversed phase (RP) column, peaks arising from both the anionic LAS and the non-ionic OPEO were detected after positive ionisation, while in negative ionisation mode, OPEO were discriminated and only the anionic surfactant was observed. Surprisingly, the relative sensitivity for detection of LAS was approximately five times higher in positive ion mode, which led the authors to the conclusion that this ionisation mode was desirable for quantitative work. 

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. 

Dissolved concentrations of non-ionic surfactant in estuaries are lower than those found in rivers, with reported differences of around one order of magnitude [4,11,25]. However, in some cases local sources in the estuary are the cause of high surfactant levels [9,11]. Concentrations of octylphenol ethoxylates usually amount to levels about one order of magnitude below those of the NP derivatives, reflecting the production volumes of both classes of compounds. 

Figure 13.1. Adsorption on Hg surface. Surface coverage versus square root of accumulation time for adsorption of Triton X-100 at Hg surface. Concentration of Triton X-100 (Triton X-KX) = tert. octylphenol ethoxylate with 9-10 ethoxy groups) in 0.55 mol liter" NaCl (1) 1.25, (2) 0.94, (3) 0.73, (4) 0.63, (5) 0.52 mg liter". (From Batina etal., 1985.)...

Hanioka, N., H. Jinno, Y.S. Chung, T. Tanaka-Kagawa, T. Nishimura and M. Ando. Inhibition of rat hepatic cytochrome P450 activities by biodegradation products 4-tcrt-octylphenol ethoxylate. Xenobiotica 29 873-883, 1999. 

The rate constant at the interface (kA) can be obtained as the slope of the straight line by plotting A ma(l — a) (1 — y )2 versus a (Fig. 5.3). This approach was used for describing the kinetics of the synthesis of 1-phenoxyoctane from sodium phenoxide and 1-bromooctane in a microemulsion based on the non-ionic surfactant Triton X-100, which is an octylphenol ethoxylate [27]. The total interfacial area was calculated from known values of the head group area of the non-ionic surfactant. As shown in Fig. 5.3, straight lines were obtained from which the rate constants could be obtained. From the values of kA determined at the three different temperatures, an activation energy of 85 kj mol-1 was calculated. This is a typical value for an SN2 reaction, as usually determined in homogeneous reaction media. 

The above-mentioned reaction between sodium phenoxide and 1-bromooctane to synthesise 1 -phenoxyoctane has been carried out in different types of microemulsion systems, all based on the same non-ionic surfactant, Triton X-100 (an octylphenol ethoxylate), the same surfactant concentration (20 wt.%), the same oil to water ratio (2 3) but different hydrocarbons as oil component [28]. This results in different phase volume ratios for the different hydrocarbons. A one-phase microemulsion is only obtained with toluene as oil component. The more hydrophobic oils, i.e. cumene, isooctane, hexadecane and paraffin oil, all give a microemulsion in equilibrium with an excess oil phase, i.e. a Winsor I system. With the more hydrophilic chlorobenzene as oil a microemulsion coexisting with an excess water phase, i.e. a Winsor II system, is obtained. As is also shown in Fig. 5.4, the reactivity is highest in the chlorobenzene- and the paraffin oil-based microemulsions, i.e. in the systems... 

Polychlorinated biphenyls Nonylphenol ethoxylate (NPE) Octylphenol ethoxylate (OPE) Mercury Arsenic... 

Liang, Z., Marshall, A. G., and Westmoreland, D. G., "Determination of Molecular Weight Distributions of tert-Octylphenol Ethoxylate Surfactant Polymers by Laser Desorption Fourier Transform Ion Cyclotron Resonance Mass Spectrometry and High-Performance Liquid Chromatography," Anal. Chem., 63,815-818,1991. 

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