Stearic acid vegetable oils

Esterification over Amberlyst BD20 was evaluated by processing a model mixture in a fixed-bed reactor. The model reaction mixture was prepared by dissolving 10 wt.% of pure stearic acid (> 97%, Fluka, Germany) in a low-acid vegetable oil (0.04 %) bought in the supermarket. Methanol (> 99.5%) was used without any preliminary treatment. 

SNG Substitute natural gas. soaps Sodium and potassium salts of fatty acids, particularly stearic, palmitic and oleic acids. Animal and vegetable oils and fats, from which soaps are prepared, consist essentially of the glyceryl esters of these acids. In soap manufacture the oil or fat is heated with dilute NaOH (less frequently KOH) solution in large vats. When hydrolysis is complete the soap is salted out , or precipitated from solution by addition of NaCl. The soap is then treated, as required, with perfumes, etc. and made into tablets. 

The term fat is applied to solid esters of fatty acids with glycerol (glycerides) if the fat is liquid at the ordinary temperature, it is conventionally called a fatty oil, vegetable oil or animal oil. The acids which occur most abundantly are palmitic ticid CH3(CHj),4COOH, stearic acid CH3(CH2)isCOOH and oleic acid CH3(CH2),CH=CH(CH2),C00H. Upon hydrolysis, fats yield glycerol and the alkali salts of these acids (soaps) ... 

The oleaginous phases of creams differ composi-tionally from hydrocarbon ointments. Many, but not all, creams are patterned after vanishing cream and contain considerable stearic acid. In lieu of some or all of the stearic acid, creams sometime contain long-chain waxy alcohols (cetyl, Ci6 stearyl, Ci8), long-chain esters (myristates, Ci4 palmitates, Ci6 stearates, Cig), other long-chain acids (palmatic acid), vegetable and animal oils, and assorted other waxes of both animal and mineral origin. 

The most effective lubricants are the hydrophobic stearates, such as magnesium stearate, calcium stearate, and stearic acid. Magnesium stearate is the most widely used lubricant [117,118]. Lubricants proposed as being less hydrophobic such as hydrogenated vegetable oils, polyethylene glycols, and sodium stearyl fumarate are less effective in this application [118]. 

In the characterization of alkyd resin formulations the palmitic acid to stearic acid (P/S) ratio, often used to identify the type of oil in a binder, cannot be applied as many different oils other than the traditional ones are commonly employed in industrial formulations. Moreover, they are often in mixtures, with the additional complication that fatty acids are also sometime added to the vegetable oils, thus making it impossible to rely on measured P/S values. In any case it is important to always derivatize the samples if Py-GC/MS is used and an alkyd is suspected. Phthalic anhydride will be detected also in an underivatized alkyd pyrogram however, isophthalic acid will not, leading to confusion and the possibility of uncorrected identification [92]. 

The solubility of C60 and C70 in a series of vegetable oils, namely olive, sunflower, peanut, soybean, linseed and castor oil, has been determined quantitatively spectrophotometrically. Additionally, the solubility of C60 and C70 has been determined quantitatively in the methyl esters of brassica oilseed and only qualitatively in molten cow butter, molten stearic acid and molten behenamide. The experimental results show that the solubility of fullerenes appears to be dependent on the unsaturation level of the fatty acids composing the vegetable oils being lower in oils with higher unsaturation level. The solubility has been found dependent also on the polarizability parameter of the vegetable oils. 

The major properties of nine of the principal edible vegetable oils are summarized in Tbble 2. For descriptions of the constituent acids, see also Arachidic Acid Capric Acid Caproic Acid Lauric Acid Linoleic Acid Linolenic Acid Myristic Acid Oleic Acid Palmitic Acid and Stearic Acid and Stearates. 

The vegetable oil used was rapeseed oil (Nacalai Tesque Kyoto, Japan) without further treatment. The fatty acid content of the rapeseed oil mainly consisted of unsaturated fatty acids (93 wt%), with the saturated fatty acids of palmitic and stearic acids accounting for only a small amount (7 wt%). Various fatty acids of oleic (C181), linoleic (C18 2), linolenic (C18 3), and palmitic (C16 0) acids as well as their methyl esters were purchased from Nacalai Tesque. Anhydrous methanol and distilled water were also supplied by the same company. 

Rapeseed oil and its fatty acids (stearic, palmitic, oleic, linoleic, and linolenic acids) were chosen as the samples of vegetable oil. The experiments were performed in the batch- and flow-type supercritical biomass conversion systems developed in our laboratory. For the batch-type system, a reaction vessel was made of Inconel-625 with a volume of 5 mL for the flow-type system, the supercritical treatment tube was constructed from Hastelloy stainless steel (HC 276) with length of 84 m and an id of 1.2 mm, with the total volume being about 95 mL. Detailed information about the equipment can be found elsewhere (13). 

In the present experiment, we measure the amount of the active ingredient, acetylsalicylic acid (see also Experiment 35), in common aspirin pills. Companies use different fillers and in different amounts, but the active ingredient, acetylsalicylic acid, must be the same in every aspirin tablet. We separate the acetylsalicylic acid from the filler based on their different solubilities. Acetylsalicylic acid is very soluble in ethanol, while neither starch, nor other polysaccharides, or even mono- and disaccharides used as a fillers, are soluble in ethanol. Some companies may use inorganic salts as fillers but these too are not soluble in ethanol. On the other hand, some specially formulated aspirin tablets may contain small amounts of ethanol-soluble substances such as stearic acid or vegetable oil. Thus the ethanol extracts of aspirin tablets may contain small amounts of substances other than acetylsalicylic acid. 

Extracted from the bean and often called Soyabean oil. A versatile carrier suitable for all skin types. It is comparatively high, up to 17%, in unsaturated fatty acids with the unsaturated linoleic (54%), oleic (24%), palmitic (10%), linolenic (7%) and stearic (4%). It also contains the highest amount of lecithin of any vegetable oil and the cold pressed oil is particularly high in vitamin E. It needs careful storage as it oxidizes easily. Soya oil may cause allergic reactions and has been reported to damage hair. 

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