Esters of Higher Aliphatic Acids

Esters of unsaturated acids are of experimental interest because of their ability to be converted into insoluble products. Cellulose crotonate, upon heating in the presence of air, or upon exposure to ultraviolet light, becomes completely insoluble. This action may be accelerated by the addition of small quantities of benzoyl peroxide. Esters of more active unsaturated acids, such as cellulose acetate linoleate, become insoluble upon exposure to air at ordinary temperatures.  

---

The basic types of epoxy stabilizers are glycidyl esters - condensation products of epichlorohydrin with phenols and aliphatic alcohols, epoxided esters of higher aliphatic acids, and alicyclic epoxy esters of aliphatic and aromatic acids and alcohols [246, 247, 251-256]. 

Definition.— Lipides are esters of higher aliphatic acids obtained from living tissues and characterised by insolubility in water, and solubility in the fat solvents ether, chloroform, carbon tetrachloride, Light petroleum (petrol), benzene, xylene, hot aleohol and hot acetone. 

Classification of the Lipides.—A. Simple lipidea, or true fats. Esters of higher aliphatic acids with various alcohols. Contain only C, H and 0. 

It has been found that these troubles can be significantly solved by the use of a pol5walent alcohol ester of higher aliphatic acid, higher alcohol ester of straight-... 

In 1950, Dahlquist et al. [82] reported the use of polyvinyl A -alkyl carbamates as PSA release materials. Since then, many other types of alkyl side chain polymers have been patented for use as release coatings, including copolymers based on higher alkyl acrylates or methaci ylates [83-86], polyvinyl esters of higher aliphatic fatty acids [87], higher alkyl vinyl esters or ethers and a maleic... 

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-... 

Cellulose esters, of aromatic acids, I, 320 of dibasic acids, I, 320 of higher aliphatic acids, I, 319 industrial applications, I, 322 mixed, I, 317... 

The low-volatility, flame-resistant phosphoric acid esters have maintained their position in products subjected to high levels of mechanical strain such as conveyor belts. Triphenyl phosphate, used only for molding compounds made of cellulose esters, is a practically noncombustible product that is not soluble in benzine. Tricresyl phosphate (TCP) is a flame-retardant plasticizer for PVC products subjected to heavy mechanical stress. The esters of the aliphatic dicarboxylic acids (adipic, azelaic, and sebacic acid) are used as plasticizers for PVC and PVAC. These products are resistant to cold and light. The esters of higher fatty acids such as pelargonates, laurates, palmitates, stearates, and ricinoleates are, strictly speaking, not plasticizers, but are rather used as extenders, secondary plasticizers, or lubricants. 

Esters of higher fatty adds are classified either as Kpids or lipid accompanying substances. Some of these (esters of higher fatty acids with lower aliphatic alcohols, such as ethanol) are odour-active constituents found mainly in alcohoUc beverages, but they usually only affect the taste or are flavour-indifferent substances. 

Known examples of slip agents useful in photographic materials include polyor-ganosiloxanes, higher aliphatic amides, higher aliphatic esters, metallic salts of higher aliphatic acid, and polyester compounds made of dicarboxylic acid having up to 10 carbon atoms and aliphatic or cyclic aliphatic diol. ... 

Table IV. Apparent Melting Temperature of Various Higher Aliphatic Acid Esters of Wood Prepared by the TFAA or the Chloride Method...

As the proton release is often too slow under the acidic conditions used for the diazotization of aromatic amines, syntheses of aliphatic diazo compounds by this method are carried out without an excess of mineral acid. Usually, equimolar amounts of amine, HCl and NaN02, or amine and NOCl, are used. A better alternative is nitrosation with pentyl nitrite in the presence of up to 30% acetic acid, as found by Takamura et al. (1975). Yields higher than 60% were obtained with a-amino-substituted esters of some aliphatic carboxylic acids. 

Soon after the first preparation of vinyl acetate by the reaction of acetic acid with acetylene and its polymerization by Klatte [209] in 1912, methods for its industrial-scale synthesis were developed first in Germany, then in Canada [210]. At the same time, the chemistry was extended to the preparation and polymerization of vinyl esters of other aliphatic and aromatic carboxylic acids. The new polymers found immediate uses in paints, lacquers, and adhesives. Steady improvements in the industrial-scale monomer synthesis, particularly in the discovery of new catalysts for the acetic acid-acetylene condensation and development of a low-cost synthesis route based on ethylene have made vinyl acetate a comparatively inexpensive monomer. Besides the original applications, which still dominate the major uses of poly(vinyl acetate), this polymer finds additional utility as thickeners, plasticizers, textile finishes, plastic and cement additives, paper binders and chewing gum bases, among many others. At the same time, the uses and production of polymers of the higher vinyl esters have not kept pace with that of poly(vinyl acetate), primarily due to their higher cost. Consequently, the current worldwide production of these materials remains low. 

In general the method is more satisfactory with esters of aromatic acids than with esters of aliphatic acids. Esters of alcohols other than methyl and ethyl are best treated by first converting them into methyl esters thus Heat together under reflux i ml. of the higher ester, 5 ml. of methanol and 0-2 g. of sodium methoxide. [In place of the sodium methoxide, it suffices to add o i g. of metallic sodium to the methanol.] After refluxing, distil off the excess of methanol (b.p, 65 ). The residue is then heated under reflux with benzylamine as described above. 

Direct, acid catalyzed esterification of acryhc acid is the main route for the manufacture of higher alkyl esters. The most important higher alkyl acrylate is 2-ethyIhexyi acrylate prepared from the available 0x0 alcohol 2-ethyl-1-hexanol (see Alcohols, higher aliphatic). The most common catalysts are sulfuric or toluenesulfonic acid and sulfonic acid functional cation-exchange resins. Solvents are used as entraining agents for the removal of water of reaction. The product is washed with base to remove unreacted acryhc acid and catalyst and then purified by distillation. The esters are obtained in 80—90% yield and in exceUent purity. 

---