Surfactants linear alkylbenzene

Anionics are the largest class of surfactants in terms of volume, and include the work-horse surfactants, linear alkylbenzene sulfonate (LAS), alcohol sulfate (AS) and alcohol ether (or ethoxy) sulfate (AES). Cationic surfactants generally include various quaternary salts, used predominantly as fabric conditioners ( fabric softeners ), anti-static agents and anti-microbial agents. Amphoteric surfactants represent the smallest class of surfactants, and generally are used when solubility, mildness and compatibility issues are important. 

Anionic surfactants Linear alkylbenzene sulfonate, secondary alk esulfonate, alkylsulfate, alkyl edi sulfate 10-40... 

A great deal of interest is currently focused on methyl ester sulfonates (MES) from palm and coconut derivatives with the increase in crude oil prices and the resultant increase in the prices of petrochemicals. MES offers an environment friendly and viable alternative to the old workhorse surfactant linear alkylbenzene sulfonic acid/sulfonate (LAS/LABS), which is derived from linear alkylbenzene (LAB). 

Linear paraffins in the C q to range are used for the production of alcohols and plasticizers and biodegradable detergents of the linear alkylbenzene sulfonate and nonionic types (see Alcohols Plasticizers Surfactants). Here the UOP Molex process is used to extract / -paraffins from a hydrotreated kerosine (6—8). 

The higher molecular weight unbranched C10-C18 n-olefins—not only a-olefins but also n-olefins with internal double bonds, so-called n-vj/-olefins—are important initial products for the manufacture of anionic surfactants, e.g., linear alkylbenzenes or olefinsulfonates. These linear C10-C18 olefins are manufactured technically by the following procedures ... 

Not only the linear Cl0-Cl8 a-olefins but also the linear C10-Cl8 olefins with internal double bonds, the so-called -v /-olefins, are of great importance in surfactant chemistry, n-a-Olefins and n-y-olefins have the same suitability for the manufacture of linear alkylbenzenes, the most important synthetic anionic surfactants, by alkylation of benzene. Nowadays medium molecular weight n- /-olefins are industrially produced by two processes the catalytic dehydrogenation of the corresponding n-alkanes [4,28] and the cometathesis of low and high molecular weight n-v /-olefins, obtained by double-bond isomerization of the isomeric n-a-olefins [29]. 

FIG. 8 Reduction in surface tension of 0.05% solutions of linear alkylbenzene-sulfonate-a-olefinsulfonate (LABS-AOS) mixed surfactant system. (From Ref. 3.)... 

Surfactants, such as linear alkylbenzene sulfonates (LAS) and alkylphenol ethoxylates, are present in whitewaters because of their use as cleaning agents or as additives in antifoamers, deinkers, dispersants, etc. The non-ionic surfactants alkylphenol ethoxylates (APEO) degrade to nonylphenol (NP) or to a... 

The trend of discovering the analytical field of environmental analysis of surfactants by LC-MS is described in detail in Chapters 2.6-2.13 and also reflected by the method collection in Chapter 3.1 (Table 3.1.1), which gives an overview on analytical determinations of surfactants in aqueous matrices. Most methods have focused on high volume surfactants and their metabolites, such as the alkylphenol ethoxylates (APEO, Chapter 2.6), linear alkylbenzene sulfonates (LAS, Chapter 2.10) and alcohol ethoxylates (AE, Chapter 2.9). Surfactants with lower consumption rates such as the cationics (Chapter 2.12) and esterquats (Chapter 2.13) or the fluorinated surfactants perfluoro alkane sulfonates (PFAS) and perfluoro alkane carboxylates (PFAC) used in fire fighting foams (Chapter 2.11) are also covered in this book, but have received less attention. 

The quantitative environmental analysis of surfactants, such as alcohol ethoxylates, alkylphenol ethoxylates (APEOs) and linear alkylbenzene sulfonates (LASs), is complicated by the presence of a multitude of isomers and oligomers in the source mixtures (see Chapter 2). This issue bears many similarities to the quantitation problems that have occurred with halogenated aromatic compound mixtures, e.g. polychlorinated biphenyls (PCBs) [1]. 

Based on their use in industrial and domestic applications and abundance in environmental samples, six surfactants were selected by the participants of interlaboratory study I. Two different standard mixture solutions (standards II and 12) were distributed to all participants for the preparation of the calibration graphs. Standard II contained Arkopal N100 (NPEO), Marlamid DF 1218 (coconut fatty acid diethanolamide, CDEA) and Marlon A 350 (linear alkylbenzene sulfonate, LAS) at 1000 mg L-1 for each compound, while standard 12 contained Rewopol NOS 5 (nonylphenol ethoxylate sulfate, NPEO-SO4),... 

OCCURRENCE OF SURFACTANTS IN SURFACE WATERS AND FRESHWATER SEDIMENTS—II. LINEAR ALKYLBENZENE SULFONATES AND THEIR CARBOXYLATED DEGRADATION PRODUCTS... 

Surfactants and their biotransformation products enter surface waters primarily through discharges from wastewater treatment plants (WWTPs). Depending on their physicochemical properties, surface-active substances may partition between the dissolved phase and the solid phase through adsorption onto suspended particles and sediments [1,2]. Several environmental studies have been dedicated to the assessment of the contribution of surfactant residues in effluents to the total load of surfactants in receiving waters. This contribution reviews the relevant literature describing the presence of linear alkylbenzene sulfonates (LASs) and in particular of their degradation products in surface waters and sediments (Table 6.3.1). 

Surfactant markers were analysed by Chalaux et al. in marine sediments and sewage sludges [30] from California. The compounds investigated included APEO metabolites A9PEO1, A9PE02 and NP, as well as linear alkylbenzenes (LAB) and trialkylamines (TAM), which are residues of anionic and cationic surfactants, respectively. Sediment cores were collected up to 60 km offshore. 

A broad range of information pertaining to the toxicity of several classes of surfactants including anionic (linear alkylbenzene sulfonates (LAS), alkylether sulfates (AES), alkyl sulfates (AS), non-ionic (alkylphenol ethoxylates (APEO)), cationic (ditallow dimethyl ammonium chloride (DTDMAC)—a group of quaternary ammonium salts of distearyl ammonium chloride (DSDMAC)) and amphoteric surfactants (alkyl-betaines) is available. Several reviews of the scientific literature have been published [3-5,20]. 

Surfactants elimination via bile is faster in fed than in unfed fish [12,40], due to the higher secretion of bile into the digestive tract when fed. The fastest and slowest surfactants excreted were the linear alkylbenzene sulphonates (C12) and the alkyl sulphates (especially the C12-15) [12], respectively. Depuration of NP is quite rapid, 1.8-20 days in fathead minnows [32] and 4 days in the Atlantic salmon [41]. Within the same organism, differences in tissues were observed, with values of 20 h for adipose tissue and 18.5 h for muscle of rainbow trout [24]. The elimination rate of non-ionic surfactants is directly proportional to the ethoxylate unit number and inversely proportional to the alkyl chain length [33]. Average elimination rates (k2) of NPE02.8 and NP in clams were 1.8 and 1.4 per day, respectively [21], and decreasing k2 values from 0.19 to 0.001 per day were obtained from butylphenol to dodecylphenol in salmon [42]. 

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