2- lauric

Fig. XII-10. Variation of n with load. The data are the friction of copper lubricated with lauric acid (------) and with octacosanoic acid (—). (From Ref. 23.)...

Davies [114] found that the rates of desorption of sodium laurate and of lauric acid films were in the ratio 6.70 1 at 21.5°C at molecular areas of 90 and 60 per molecule, respectively. Calculate o. the potential at the plane CD in Fig. XV-12. 

Another ester synthesis employs the reaction of a long-chain ketone and pentaerythritol in xylene or chlorobenzene (14). Mixed esters have been produced using mixed isostearic and cyclohexane carboxyUc acids in trihromophosphoric acid, followed by reaction with lauric acid (15). 

A USDA report indicates that between 1967 and 1988, butter consumption remained stable at 2 kg per capita, margarine dropped from 5.1 to 4.7 kg, and measured total fat intake per day dropped from 84.6 to 73.3 g (14). This study also projects that the reduced consumption of tropical oils is only temporary and will return to former use levels, possibly even higher. One reason for this projected rise in tropical oil consumption is the knowledge of the beneficial effects of medium-chain length acids high in lauric oils. There is a keen interest in omega-3 fatty acids, as well as linoleic acid, contained in fish oils. 

Fats and oils may be synthesized in enantiomerically pure forms in the laboratory (30) or derived from vegetable sources (mainly from nuts, beans, and seeds), animal depot fats, fish, or marine mammals. Oils obtained from other sources differ markedly in their fatty acid distribution. Table 2 shows compositions for a wide variety of oils. One variation in composition is the chain length of the fatty acid. Butterfat, for example, has a fairly high concentration of short- and medium-chain saturated fatty acids. Oils derived from cuphea are also a rich source of capric acid which is considered to be medium in chain length (32). Palm kernel and coconut oils are known as lauric oils because of their high content of C-12 saturated fatty acid (lauric acid). Rapeseed oil, on the other hand, has a fairly high concentration of long-chain (C-20 and C-22) fatty acids. 

Hlkanolamides. The fatty acid alkanolamides are used widely ia shampoo formulations as viscosity and lather builders. They are formed by the condensation of a fatty acid with a primary or secondary alkanolamine. The early amides were compositions of 2 1 alkanolamine to fatty acid. Available technology allows the formation of amides with a 1 1 ratio of these additives. These amides are classified as superamide types. The typical amide used ia shampoo preparations usually contains the mono- or diethanolamine adduct, eg, lauric diethanolamide [120-40-1] (see Amides, fatty acid). 

Concrete. Hydrocarbon extracts of plant tissue, concretes are usually soHd to semisoHd waxy masses often containing higher fatty acids such as lauric, myristic, palmitic, and stearic as well as many of the nonvolatiles present in absolutes. 

More frequentiy, alkyd resias are described by a combiaed classification ia terms of thek oil length, the type of fatty acids, and any unusual kigredients. Such descriptions as an isophthaUc, very long tall oil alkyd a medium oil dehydrated castor-PE ( pentaerythritol, not polyethylene) alkyd or a short oil lauric-ben2oic alkyd, immediately project the general properties of the reski. 

Lauramide has been prepared by passing ammonia gas through lauric acid in the presence of metallic oxides, specifically a complex mixture of Si02—AI2O2—Fe202—CaO—SO in the ratio of 24 16 3 47 10. The oxides, which are hydrated during amidation, can be regenerated by calcination (12,13). 

Amide yields of up to 90—95% are reported from lauric acid and urea (1 1 mole ratio) by ramping the reaction temperature from 140 to 190°C over 4 hours. Oleic, stearic, linoleic, and ricinoleic acids gave similar results (19,20). The reaction does not form significant quantities of bisamides, but rehes on the decomposition of a substituted urea amide, releasing CO2 and NH. ... 

Many primary fatty amides which are available from various manufacturers are Hsted in Table 3. In 1986 approximately 55,000 metric tons of amides and bisamides were produced world wide (58), the majority of which are bisamides, followed in volume by primary amides. Most of these products are shipped in sohd form in bag or dmm quantities. Major producers of primary fatty amides are Akzo, Glyco, Humko, and Sherex. Bisamides are produced by Akzo, Milacron, and Syntex. There are over 100 producers of alkanolamides in the world, most of which are small specialized manufacturers to a specific industry. GAP, Henkel, Sherex, and Witco are among the principal producers. The most widely used alkanolamides are the Ai,Ai-bis(2-hydroxyethyl) fatty amides, mostly produced from middle-cut coco fatty acids (6% capryflc, 7% capric, 51% lauric, 19% myristic, 9% palmitic, and 2% stearic acids). An estimated 77,000 metric tons of alkanolamide was produced worldwide in 1986 (59). 

Activators. Activators are chemicals that increase the rate of vulcanization by reacting first with the accelerators to form mbber soluble complexes. These complexes then react with the sulfur to achieve vulcanization. The most common activators are combinations of zinc oxide and stearic acid. Other metal oxides have been used for specific purposes, ie, lead, cadmium, etc, and other fatty acids used include lauric, oleic, and propionic acids. Soluble zinc salts of fatty acid such as zinc 2-ethyIhexanoate are also used, and these mbber-soluble activators are effective in natural mbber to produce low set, low creep compounds used in load-bearing appHcations. Weak amines and amino alcohols have also been used as activators in combination with the metal oxides. 

Four columns are needed to produce the desired products. Considering the Sharp Distillation Sequencing heuristics, heuristic (/) does not apply, as there is more than one product in this mixture. Fatty acids are moderately corrosive, but none is particularly more so than the others, so heuristic (2) does not apply. The most volatile product, the caproic and capryflc mixture, is a small (10 mol %) fraction of the feed, so heuristic (3) does not apply. The least volatile product, the oleic—stearic acids, is 27% of the feed, but is not nearly as large as the capric—lauric acid product, so heuristic (4) does not apply. The spht between lauric and myristic acids is closest to equimolar (55 45) and is easy. Therefore, by heuristic (5) it should be performed first. The boiling point list implies that the distillate of the first column contains caproic, capryflc, capric, and lauric acids. This stream requires only one further separation, which by heuristic (/) is between the caproic—capryflc acids and capric—lauric acids. 

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