Esters higher fatty

Hydrogenolysis Process. Patty alcohols are produced by hydrogenolysis of methyl esters or fatty acids ia the presence of a heterogeneous catalyst at 20,700—31,000 kPa (3000—4500 psi) and 250—300°C ia conversions of 90—98%. A higher conversion can be achieved using more rigorous reaction conditions, but it is accompanied by a significant amount of hydrocarbon production. 

Chemical Composition. Wool wax is a complex mixture of esters of water-soluble alcohols (168) and higher fatty acids (169) with a small proportion (ca 0.5%) of hydrocarbons (170). A substantial effort has been made to identify the various components, but results are compHcated by the fact that different workers use wool waxes from different sources and employ different analytical techniques. Nevertheless, significant progress has been made, and it is possible to give approximate percentages of the various components. The wool-wax acids (Table 9) are predominantiy alkanoic, a-hydroxy, and CO-hydroxy acids. Each group contains normal, iso, and anteiso series of various chain length, and nearly all the acids are saturated. 

The higher fatty acids undergo decarboxylation and other undesirable reactions when heated at their boiling points at atmospheric pressure. Hence they are distilled at reduced pressure (15,16). Methyl esters boil at lower temperatures than acids at the same pressure as the result of the absence of hydrogen bonding (17). A procedure for calculation of the vapor pressures of fatty acids at various temperatures has been described (18). 

Solids. —It may Idc a hydrocM bon (c .g., paraffin wa, naphthalene) highei alcohol eg., cetyl alcohol) aldehyde e.g., z5-hydroxybenzaldehyde) ketone and qiiinonc e.g., benzo-phenone, camphor) acid (higher fatty, e.g., palmitic acid or aromatic acid) ester (of glycerol, phenols or aromatic alcohols) phenol e.g., thymol),... 

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. 

On-line SFE-pSFC-FTIR was used to identify extractable components (additives and monomers) from a variety of nylons [392]. SFE-SFC-FID with 100% C02 and methanol-modified scC02 were used to quantitate the amount of residual caprolactam in a PA6/PA6.6 copolymer. Similarly, the more permeable PS showed various additives (Irganox 1076, phosphite AO, stearic acid - ex Zn-stearate - and mineral oil as a melt flow controller) and low-MW linear and cyclic oligomers in relatively mild SCF extraction conditions [392]. Also, antioxidants in PE have been analysed by means of coupling of SFE-SFC with IR detection [121]. Yang [393] has described SFE-SFC-FTIR for the analysis of polar compounds deposited on polymeric matrices, whereas Ikushima et al. [394] monitored the extraction of higher fatty acid esters. Despite the expectations, SFE-SFC-FTIR hyphenation in on-line additive analysis of polymers has not found widespread industrial use. While applications of SFC-FTIR and SFC-MS to the analysis of additives in polymeric matrices are not abundant, these techniques find wide application in the analysis of food and natural product components [395]. 

Hexanedioic acid is used in the manufacture of nylon-6, 6. Esters of benzoic acid are used in perfumery. Sodium benzoate is used as a food preservative. Higher fatty acids are used for the manufacture of soaps and detergents. 

This view of the process of spreading and the conditions of equilibrium possesses certain advantages because many solids such as the fatty esters and higher fatty acids spread upon water and their spreading coefficients can only be determined by a direct measure of the film pressure which exists when equilibrium is attained. 

Naoe et al. [239] used the sugar ester DK-F-110, a mixture of sucrose esters of fatty acids, as a nonionic surfactant along with isopropyl alcohol and hexane in a reverse micellar system to extract cytochrome C. This surfactant has a critical micellar concentration of 0.5 g/1 and HLB of 11. Aqueous phase pH was found to have a major role in the forward extraction and optimum extraction was achieved at pH 8.0. However, for optimum back extraction, addition of isopropyl alcohol at 20 vol.% was found to be very essential. Further, the esterification reaction rate of Rhizopus delemar lipase was found to be maximum in DK-F-110 systems and also higher than those obtained in AOT and lecithin-RMs at a water concentration of 0.25 mol l h... 

In perfumery, acetates are the most important aliphatic esters formates do not keep well. Animal and fatty notes become more pronounced in esters of higher fatty acids. Acetates of alcohols up to C(, are used principally for fruity notes, whereas the acetates of Cg, Cio, and C12 alcohols are employed for blossom fragrances and for flower notes in general. Lauryl acetate in particular is also used for conifer notes. 

There are several plasticizers for PVC that may be used in propellants. Weil (19) mentions sebacates, phthalates, adipates, and glycol esters of higher fatty acids as being desirable. Dibutyl sebacate, dioctyl sebacate, and 2-ethylhexyl adipate are all good. The plasticizer has a most important effect on the physical properties of the cured propellant and the variation of these properties with temperature. Long chain, aliphatic plasticizers impart improved low temperature flexibility, and hence are preferable to aromatic plasticizers such as the phthalates. An increase in plasticizer viscosity leads to an increase in viscosity of the mixed pro-... 

FAT. A glycery l ester of higher fatty acids such as stearic and palmitic. Such cslcrs and their mixtures are solids at room temperature and exhibit crystalline structure. Lard and tallow are examples. There is no chemical difference between a lal and an oil. the only dislinclion being that lats are solid at room temperature and oils are liquid. The term lal usually refers to triglycerides specifically, whereas lipid is all-inclusive. 

The chemical composition of camauba wax comprises 84 -85% of alkyl esters of higher fatty adds. Of these esters only 8-9% (wax basis) are simple esters of normal acids. The other esters are acid esters 8-9%, diesteis 19-21%, and esters of hydroxylated acids 50-53% (was basis) of which about one-third are unsaturated. It is the hydroxylated saturated esters that give camauba its extreme hardness, whereas the esters of the hydroxylated linsatiiraled fatty adds produce the outstanding luster to polishes. 

SVOCs responsible for the fogging effect paraffins, higher fatty acids and esters, phthalates, phosphoric acid esters, organosilicon compounds, haloge-nated hydrocarbons, oxygen, nitrogen and sulfur compounds. 

Mestres, M., M.P. Marti, O. Busto, et al., 2000. Headspace solid phase microextraction of higher fatty acid ethyl esters in white rum aroma. J. Chromatogr. A 881 583-590. 

In order to expand the worldwide market, considerable efforts are being devoted to improve the image of Madeira wine. Consequently, their characteristics have to be well defined. So, in order to define and describe the particular characteristics and the authenticity of the product, secondary metabolites of grape and wines mainly linked to a specific variety, must be deeply studied. In Madeira wine, these compounds are mainly included in the chemical classes of mono and sesquiterpenoids C13 norisoprenoid higher alcohols, ethyl esters, volatile fatty acids, carbonyl compounds, sulfur compounds, furanic compounds, lactones, and polyphenols. 

Watabe et al. [99] identified trace amounts of phthalate esters, polyaromatic hydrocarbons, higher fatty acids and their esters in rain water by means of a gas chromatography mass spectrometer-computer system. 

De Vries, B. (1963) Quantitative separations of higher fatty acid methyl esters by adsorption chromatography on silica impregnated with silver nitrate. J. Am. Oil Chem. Soc., 40, 184-186. 

Esters are common derivatives of carboxyl groups. Methyl esters are the most often used as they have a sufficient volatility even for the chromatography of higher fatty acids... 

Olestra occurs as a solid, soft gel, or liquid at room temperature depending on the fatty acids used in manufacture. It is a mixture of the octa-, hepta-, and hexa-esters of sucrose prepared by the reaction of sucrose with edible C12 to C20 and higher fatty acid methyl esters. It is insoluble in water and soluble in common lipid solvents. 

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