Palmitic anhydride

Palmitic acid anhydride (hexadecanoic anhydride) [623-65-4] M 494.9, m 63-64 , 64 , d 0.838, n 1.436. It is moisture sensitive and hydrolyses in water. Purified by refluxing with acetic anhydride for Ihr, evaporating and freeing the residue of acetic acid and anhydride by drying the residue at high vac and crystallising from pet ether at low temperature. 

ImCOCF3 phthalic anhydride 89 ImCOCF3 palmitic anhydride 54... 

ImCOCCl3 phthalic anhydride 89 ImCOCCl3 palmitic anhydride 50... 

Figure 12.12 THM GC/MS curves of a Winsor Newton lemon alkyd paint (a) and of an alkyd sample taken from Fontana s work Concetto spaziale (1961) (b). Peak assignments 1, 1,3 dimethoxy 2 propanol 2, 1,2,3 trimethoxy propane 3, 3 methoxy 1,2 propandiol 4, 4 chloro benzenamine 5, 3 methoxy 2,2 bis(methoxymethyl) 1 propanol 6, 3 chloro N methyl benzenamine 7, 3 methoxy 2 methoxymethyl 1 propanol 8, 4 chloro N methyl benzenamine 9, phthalic anhydride 10, 3 chloro 4 methoxy benzenamine 11, suberic acid dimethyl ester 12, dimethyl phthalate 13, azelaic acid dimethyl ester 14, sebacic acid dimethyl ester 15, palmitic acid methyl ester 16, oleic acid methyl ester 17, stearic acid methyl ester 18, 12 hydroxy stearic acid methyl ester 19, 12 methoxy stearic acid methyl ester 20, styrene 21, 2 (2 methoxyethoxy) ethanol 22, 1,1 oxybis(2 methoxy ethane) 23, benzoic acid methyl ester 24, adipic acid dimethyl ester 25, hexadecenoic acid methyl ester 26, dihydroisopimaric acid methyl ester 27, dehydroabietic acid methyl ester 28, 4 epidehydroabietol...

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]. 

Polysorbate 60 occurs as a yellow to orange colored, oily liquid or semigel. It is a mixture of stearate and palmitate partial esters of sorbitol and sorbitol anhydrides condensed with approximately 20 moles of ethylene oxide (C2H40) for each mole of sorbitol and its mono- and dianhydrides. It is soluble in water, in aniline, in ethyl acetate, and in toluene, but it is insoluble in mineral oil and in vegetable oils. 

A rather unusual solvent system for sucrose, namely, molten chloroacetic acid, was used by Lorand,160 who prepared sucrose esters from palmitic anhydride dissolved in this medium. It is unlikely that the glycosidic link in the sucrose is unaffected under these conditions. 

Palmitic anhydride (10.104 mmol) was dissolved in 20 ml THF and 3 mol pyridine, then stirred at ambient temperature, and slowly treated with triethylene glycol (10.104 mmol). After stirring 1 hour, THF was removed and the mixture poured into ice-cold 10% sulfuric acid. The aqueous layer was extracted three times with 30 ml... 

The specimens were treated according to the method of Nakagami and coworkers [17,18]. Japanese linden Tilia japonica Smik.) was treated with trifluoroacetic acid anhydride and the fatty acids (TFAA method), which included acetic acid, propionic acid, valeric acid, hexanoic acid, decanoic acid, lauric acid, and palmitic acid. Dynamic measurements were made with a torsion pendulum apparatus under a vacuum. An increasing temperature rate was 2°C/min. The amount of introduced side chain per gram of wood is about 4-6 mmol/g [16]. The chemical structure of the treated wood is presented by the formula ... 

Pyridine is used in catalytic amounts and acylpyridinium salts are assumed to be the reactive acylating agents. The method can be applied to the synthesis of both symmetrical and unsymmetrical acid anhydrides. " These can also be obtained in many cases directly from the acid halide and the sodium carbox-ylate without using a solvent or a catalyst. Tiiis approach has been described for a number of mixed acid anhydrides. Thus acetic palmitic anhydride (70%), butyric myristic anhydride (81%) and caproic lauric anhydride (85%) were prepared by heating the components for 2 h at 90 °C. 75 These anhydrides were successfully employed for the N-acylation of amino sugars. 7 ... 

The Span type materials are partial esters of the common fatty acids flauric, palmitic, stearic, and oleic) and hexitol anhydrides (hexjtans and hexides), derived from sorbitol. 

FIGURE 21.3 Ion trap mass spectrum of ESI-MS of [OPO + Li - OCOOH]+ at m/z 583.5. For abbreviations, see Figure 21.2. P CH=CHCOOH is the oc,p-unsaturated palmitic acid from the sn-2 position 0 CH=CHCOOH is a,p-unsaturated oleic acid from the. n-1,3 position (not detected) C3H4O is the loss of glycerol backbone to form acid anhydride of two fatty acids (6) P"CH=C=0 is palmitoyl ketene from the sn-2 position and 0"CH=C=0 is oleoyl ketene from the. n-1,3 position. 

Miladinov et al. reported the preparation of starch-fatty acid esters by reactive extrusion of plasticized starch and acid anhydrides (acetic, propionic, heptanoic and palmitic anhydrides) in the presence of sodium hydroxide as a catalyst [87]. Starch esters have been prepared by REX using maleic anhydride (MA) as a cyclic dibasic acid anhydride in the presence of 20 wt% glycerol as plasticizer. This material was melt-blended with biodegradable polyester. 

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