Azelates

LEED See low energy electron dilTraction. lei See chelate effect, iepargylic acid See azeleic acid. 

Lubricants, Fuels, and Petroleum. The adipate and azelate diesters of through alcohols, as weU as those of tridecyl alcohol, are used as synthetic lubricants, hydrauHc fluids, and brake fluids. Phosphate esters are utilized as industrial and aviation functional fluids and to a smaH extent as additives in other lubricants. A number of alcohols, particularly the Cg materials, are employed to produce zinc dialkyldithiophosphates as lubricant antiwear additives. A smaH amount is used to make viscosity index improvers for lubricating oils. 2-Ethylhexyl nitrate [24247-96-7] serves as a cetane improver for diesel fuels and hexanol is used as an additive to fuel oil or other fuels (57). Various enhanced oil recovery processes utilize formulations containing hexanol or heptanol to displace oil from underground reservoirs (58) the alcohols and derivatives are also used as defoamers in oil production. 

Raw Materials. PVC is inherently a hard and brittle material and very sensitive to heat it thus must be modified with a variety of plasticizers, stabilizers, and other processing aids to form heat-stable flexible or semiflexible products or with lesser amounts of these processing aids for the manufacture of rigid products (see Vinyl polymers, vinyl chloride polymers). Plasticizer levels used to produce the desired softness and flexibihty in a finished product vary between 25 parts per hundred (pph) parts of PVC for flooring products to about 80—100 pph for apparel products (245). Numerous plasticizers (qv) are commercially available for PVC, although dioctyl phthalate (DOP) is by far the most widely used in industrial appHcations due to its excellent properties and low cost. For example, phosphates provide improved flame resistance, adipate esters enhance low temperature flexibihty, polymeric plasticizers such as glycol adipates and azelates improve the migration resistance, and phthalate esters provide compatibiUty and flexibihty (245). 

Low Temperature Performance. The abihty of plasticized PVC to remain flexible at low temperatures is of great importance in certain apphcations, eg, external tarpaulins or underground cables. Eor this property the choice of the acid constituent of the plasticizer ester is also important. The linear aUphatic adipic, sebacic, and azeleic acids give excellent low temperature flexibiUty compared to the corresponding phthalates and trimeUitates (Pig. 3). 

Diesters. Many of the diester derivatives are commercially important. The diesters are important plasticizers, polymer intermediates, and synthetic lubricants. The diesters of azelaic and sebacic acids are useflil as monomeric plasticizing agents these perform weU at low temperatures and are less water-soluble and less volatile than are diesters of adipic acid. Azelate diesters, eg, di- -hexyl, di(2-ethylhexyl), and dibutyl, are useflil plasticizing agents for poly(vinyl chloride), synthetic mbbers, nitroceUulose, and other derivatized ceUuloses (104). The di-hexyl azelates and dibutyl sebacate are sanctioned by the U.S. Food and Dmg Administration for use in poly(vinyl chloride) films and in other plastics with direct contact to food. The di(2-ethylhexyl) and dibenzyl sebacates are also valuable plasticizers. Monomeric plasticizers have also been prepared from other diacids, notably dodecanedioic, brassyflc, and 8-eth5lhexadecanedioic (88), but these have not enjoyed the commercialization of the sebacic and azelaic diesters. 

The mechanism of inhibition by the salts of the long chain fatty acids has been examined . It was concluded that, in the case of the lead salts, metallic lead was first deposited at certain points and that at these points oxygen reduction proceeded more easily, consequently the current density was kept sufficiently high to maintain ferric film formation in addition, any hydrogen peroxide present may assist in keeping the iron ions in the oxide film in the ferric condition, consequently the air-formed film is thickened until it becomes impervious to iron ions. The zinc, calcium and sodium salts are not as efficient inhibitors as the lead salts and recent work has indicated that inhibition is due to the formation of ferric azelate, which repairs weak spots in the air-formed film. This conclusion has been confirmed by the use of C labelled azelaic acid, which was found to be distributed over the surface of the mild steel in a very heterogeneous manner. ... 

Early studies on oxide films stripped from iron showed the presence of chromium after inhibition in chromate solutionand of crystals of ferric phosphate after inhibition in phosphate solutions. More recently, radio-tracer studies using labelled anions have provided more detailed information on the uptake of anions. These measurements of irreversible uptake have shown that some inhibitive anions, e.g. chromateand phosphate are taken up to a considerable extent on the oxide film. However, other equally effective inhibitive anions, e.g. benzoate" pertechnetate and azelate , are taken up to a comparatively small extent. Anions may be adsorbed on the oxide surface by interactions similar to those described above in connection with adsorption on oxide-free metal surfaces. On the oxide surface there is the additional possibility that the adsorbed anions may undergo a process of ion exchange whereby... 

The preparation of several medium- and large-sized 2-carbo-methoxycycloalkanones has been accomplished by treatment of the cycloalkanone with sodium triphenylmethyl, followed by carbonation with dry ice, and esterification with diazomethane. 1 The yields are good but the procedure is laborious. The synthesis of 2-carbomethoxycycIooctanone via the Dieckmann cyclization of dimethyl azelate with sodium hydride yields 48% of this product when the procedure is carried out over a 9-day period.3... 

E.g.perfluomonanoic acid and methyl azelate Weiper A, Schafer HJ unpublished results... 

C22H24O7 70653-29-1) see Latamoxef monomethyl azelate (CioH,04 2/04-79-0) see Misoprostol monomethyl 5-nitroisophthalate... 

BEHA (1) V,V-Bis-(2-hydroxyethyl) alkyl (Cg-Cis) amine (2) Bis(2-ethylhexyl)azelate... 

Diethyl azelate, 45, 31 Diethylbenzene as solvent for decomposition of diphenyliodonium-2-carboxylate in preparation of... 

Polyethylene adipate Polyethylene suberate Polyethylene azelate Polyethylene sebacate Polyethylene decamethylate Polytetraunethylene succinate Polytetramethylene adipate Polytetramethylene sebacate Polyhexamethylene sebacate Poly-2,2-dimethyItrimethylene succinate... 

Figure 6. Relationship between Tm and the biodegradability of polyesters by R> delemar (a) and R> arrhizus (b) lipases, and PEA-degrading enzyme from Penicillium sp. strain ll+-3 (c). PESu polyethylene suberate PEAz polyethylene azelate PESE polyethylene sebacate PEDe polyethylene decamethylate PBS polytetramethyl-ene succinate PBA polytetramethylene adipate PBSE polytetra-methylene sebacate PHSE polyhexamethylene sebacate PPL poly-propiolactone.

Materials. The following materials were used as received adipic acid 99% (AA, Aldrich), azeleic acid 90% (AZA, Emerox 1144, Huls), sebacic acid 99% (SA, Aldrich), dodecanedioic acid 99% (DDA, DuPont),... 

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