Nonionic surfactants fatty acid methyl esters

Fatty acids or their derivatives are connected to a variety of hydrophilic head groups through esterification of fatty acids or transesterification using fatty acid methyl esters or triglycerides as depicted in Scheme 1.8. Hydrophilic head groups that are used to prepare nonionic ester surfactants fall into several of the following subcategories. 

Up to early 1990s, it was assumed that oxyethylation can occur only when the hydrophobic reagent had a labile hydrogen [1-3,5]. Thus, fatty acid methyl esters (FAME) were not considered as a raw material for the direct synthesis of nonionic surfactants with a polyoxyethylene chain. However, esters of fatty acids and PEG monomethyl ethers were known and their properties were described [6]. They were synthesized in a two-step process. Methanol was oxyethylated to PEG monomethyl ether that was then converted into the final product by transesterification with FAME or by esterification with fatty acids, carried out in the presence of an alkaline B or an acid catalyst, respectively. Esters of typical nonionics were synthesized in similar ways and their properties were described [7-9]. 

Behler, A., Syldath, A. 2000. Fatty acid methyl ester ethoxylates—a new class of nonionic surfactants. Proceedings of the 5th World Surfactants Congress. Firenze, 1 382-391. 

Mono- and disaccharides are highly hydrophilic substances. They are produced in large volumes, are available in highly pure form, and are relatively cheap [4,5]. They may be, and indeed have been, used as hydrophilic substrates for the synthesis of nonionic surfactants. In 1999, the worldwide production of the latter was about 3.6 3.8 million metric tons, i.e., approximately 38% of total surfactant production [6]. The majority of the conventional nonionic surfactants are oligooxyethylene (and oxypropylene) chain-containing compounds obtained in the reaction of oxirane (ethylene oxide) or methyloxirane (propylene oxide) with hydrophobic intermediates that contain a functional group with an active hydrogen atom [7]. Only recently, the direct reaction of oxirane with fatty acid methyl esters in the... 

Description. Surfactants of this class are better known as sugar esters or sucrose esters. The sucrose esters are obtained by transesterification of sucrose with fatty acid methyl esters or triglycerides, leaving methanol or glycerol as by-products, respectively- Mono- and diesters are the major products. Due to the steric effects,-primary hydroxyl groups are almost exclusively subject to esterification. Both types of esters exhibit the general properties of common nonionics (i.e., ethoxylated alcohols). 

In general and with respect to RR, - surfactants are the most interesting ingredients of d. because aside of LAS (linear alkylbenzene sulfonate), almost all major surfactants are derived from - fats and oils. Anionic and nonionic surfactants are used in heavy-duty d. for soil removal, pigment dispersion, desirable foaming, wetting, and solubilization of all kinds of stains. From the RR-derived products, mainly - fatty alcohol sulfates and fatty alcohol ether sulfates are, and - a-sulfo fatty acid methyl esters may be, used. - Fatty alcohol ethox-ylates are added as nonionic surfactants and impart detergency at lower temperatures and for synthetic... 

F. are primarily used as intermediates for the commercial production of - fatty alcohols. They are also an important starting material to make - fatty acid ethanolamides and are the base for making a relatively new class of - surfactants - a-sulfo fatty acid methyl esters. F. react with ethyleneoxide in the presence of hydrotalcite [12304-65-3] to yield nonionic surfactants by inserting EO in the ester function. 

Higher molecular primary unbranched or low-branched alcohols are used not only for the synthesis of nonionic but also of anionic surfactants, like fatty alcohol sulfates or ether sulfates. These alcohols are produced by catalytic high-pressure hydrogenation of the methyl esters of fatty acids, obtained by a transesterification reaction of fats or fatty oils with methanol or by different procedures, like hydroformylation or the Alfol process, starting from petroleum chemical raw materials. 

The reaction between dialkanolamines with organic acids or better still with their methyl esters gives the well known dialkanolamides. This reaction is used industrially for the synthesis of diethanolamides of fatty acids, which are well known nonionic surfactants (reaction 19.1) [1-10] ... 

These practically important nonionic surfactants are produced by interaction of a fatty acid, its methyl ester, or another derivative and aminoalcohol. Thus, about equal mole fraction of lauric acid and 2-aminoethanol at 150 °C yield lauric ethanolamide ... 

Alkoxylation catalysts have been developed that allow the ready conversion of methyl esters, as well as their precursor triglycerides, into nonionic surfactants. Methyl esters are produced from triglycerides (see Figure 13.4), or by esterifying fatty acids with methanol. 

However, tallow is composed of -30% C16 and 70% C18 chains with substantial unsaturation. The choices of carbon numbers available are limited by the type of oil used as a feed material. Coconut oil is -50% Cj2 with up to 20% and -15% each of Cs io and Cig ig. Palm kernel oil has a similar distribution. However, tallow is mostly Cjg-Cig. The shorter chain C12-C14 fatty acids and methyl esters derived from coconut and palm kernel oil are key starting materials for a host of surfactant derivatives in each of the major categories (anionics, cationics, nonionics, and amphoterics). 

Hydrogenolysis of fatty acids and their methyl esters gives alcohols used for the manufacture of nonionic surfactants. 

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