Acetate Propionate

Only esters containing two a-hydrogen atoms (ethyl acetate, propionate, n-butyrate, etc.) can be condensed with the aid of sodium alkoxides. For esters with one a-hydrogen atom, such as ethyl tsobutyrate, the more powerful base sodium triphenylmethide PhaC Na leads to condensation with the formation of ethyl a-tsobutyrylisobutyrate ... 

Acid Anhydrides. Symmetrical anhydrides of monocarboxylic acids, when unsubstituted, are named by replacing the word acid by anhydride. Anhydrides of substituted monocarboxylic acids, if symmetrically substituted, are named by prefixing bis- to the name of the acid and replacing the word acid by anhydride. Mixed anhydrides are named by giving in alphabetical order the first part of the names of the two acids followed by the word anhydride, e.g., acetic propionic anhydride or acetic propanoic anhydride. Cyclic anhydrides of polycarboxylic acids, although possessing a... 

Cellulose-acetate-propionate resin Aromatic nylons... 

Cellulose Acetate, Propionate, and Butyrate. Cellulose acetate is prepared by hydrolyzing the triester to remove some of the acetyl groups the plastic-grade resin contains 38 to 40%... 

One of the most sensitive tests of the dependence of chemical reactivity on the size of the reacting molecules is the comparison of the rates of reaction for compounds which are members of a homologous series with different chain lengths. Studies by Flory and others on the rates of esterification and saponification of esters were the first investigations conducted to clarify the dependence of reactivity on molecular size. The rate constants for these reactions are observed to converge quite rapidly to a constant value which is independent of molecular size, after an initial dependence on molecular size for small molecules. The effect is reminiscent of the discussion on the uniqueness of end groups in connection with Example 1.1. In the esterification of carboxylic acids, for example, the rate constants are different for acetic, propionic, and butyric acids, but constant for carboxyUc acids with 4-18 carbon atoms. This observation on nonpolymeric compounds has been generalized to apply to polymerization reactions as well. The latter are subject to several complications which are not involved in the study of simple model compounds, but when these complications are properly considered, the independence of reactivity on molecular size has been repeatedly verified. 

Some propionic acid is converted iato herbicides (qv) such as Stam (Rohm and Haas) (3, 4 -dich1oropropionanilide) and iato ceUulose acetate propionate, a plastic sheeting and mol ding precursor. 

Acylation. Aromatic amines react with acids, acid chlorides, anhydrides, and esters to form amides. In general, acid chlorides give the best yield of the pure product. The reaction with acetic, propionic, butanoic, or benzoic acid can be catalyzed with phosphoms oxychloride or trichloride. 

Uses ndReactions. Camphene is used for preparing a number of fragrance compounds. Condensation with acids such as acetic, propionic, isobutyric, and isovaleric produce usehil isobomyl esters. Isobomyl acetate (41) has the greatest usage as a piae fragrance (81). The isobomyl esters of acryhc and methacrylic acids are also usehil ia preparing acryUc polymers. 

Formic, acetic, propionic, and butyric acids are miscible with water at room temperature. SolubiUty in water decreases rapidly for the higher alkanoic acids as the chain length increases (Table 8) (19). The solubiUty in water at pH 2—3 for unionized acids is given by the following relationship ... 

Carboxyhc acid dust and vapors are generally described as being destmctive to tissues of the mucous membrane, eyes, and skin. The small molecules such as formic, acetic, propionic, butyric, and acryUc acids tend to be the most aggressive (Table 11) (83). Formic, acetic, propionic, acryUc, and methacrylic acids have time weighted-average exposure limits of 20 ppm or lower. AcryUc acid showed an LD q of 33.5 mg/kg from oral adrninistration to rats. 

Also produces cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) mixed esters. 

Other mixed esters, eg, cellulose acetate valerate [55962-79-3] cellulose propionate valerate [67351-41-17, and cellulose butyrate valerate [53568-56-2] have been prepared by the conventional anhydride sulfuric acid methods (25). Cellulose acetate isobutyrate [67351-38-6] (44) and cellulose propionate isobutyrate [67351-40-0] (45) have been prepared with a 2inc chloride catalyst. Large amounts of catalyst and anhydride are required to provide a soluble product, and special methods of delayed anhydride addition are necessary to produce mixed esters containing the acetate moiety. Mixtures of sulfuric acid and perchloric acid are claimed to be effective catalysts for the preparation of cellulose acetate propionate in dichi oromethane solution at relatively low temperatures (46) however, such acid mixtures are considered too corrosive for large-scale productions. 

From 1946 to mid-1987, Farbenfabriken Bayer AG in Germany was the European producer of cellulose acetate, cellulose acetate butyrate (CAB), and cellulose acetate propionate (CAP) before closing its faciUties. Bayer s exit from the cellulose acetate mixed esters business leaves Eastman Chemical Co. in the United States as the sole producer of CAB/CAP resins. 

In a similar announcement, Eastman Chemical Co. and Rhc ne-Poulenc S.A. have recently formed a 50/50 joint venture to make 59,090 metric tons /yr of cellulose acetate filter tow and fiber by the fourth quarter of 1993 (107). Eastman Chemical Co. aimounced a multimillion doUar expansion of its own filter tow capacity by approximately 11,363 metric tons/yr to be completed by mid-1991. The expansion brings the company s worldwide filter tow capacity up to 154,545 metric tons (108). Eastman Chemical Co. aimounced plans to expand the production of cellulose acetate butryates and cellulose acetate propionates by 20 and 40%, respectively, by mid-1991 (109). 

The cellulose esters with the largest commercial consumption are cellulose acetate, including cellulose triacetate, cellulose acetate butyrate, and cellulose acetate propionate. Cellulose acetate is used in textile fibers, plastics, film, sheeting, and lacquers. The cellulose acetate used for photographic film base is almost exclusively triacetate some triacetate is also used for textile fibers because of its crystalline and heat-setting characteristics. The critical properties of cellulose acetate as related to appHcation are given in Table 10. 

Table 14. Flexographic Ink Formulation Containing Alcohol-Soluble Cellulose Acetate Propionate...

Acetate propionate esters are nontoxic, exhibit excellent clarity and high tensile strength, and can be formulated into hot-melt dip coatings for food (168). Alternatively, they may be dissolved in volatile solvents and appHed to foods in the form of a lacquer coating (169). 

Desalination membranes with improved, rigid, and stable surfaces have been prepared from cellulose acetate propionate (170). These films are generally more resistant to hydrolysis than those from cellulose acetate. 

Cellulose esters, especially acetate propionate and acetate butyrate mixed esters, have found limited use in a wide variety of specialty appHcations such as in nonfogging optical sheeting (171), low profile additives to improve the surface characteristics of sheet-molding (SMC) compounds and hulk-molding (BMC) compounds (172,173), and controlled dmg release via encapsulation (174). 

Mixed esters such as cellulose acetate sulfate [51910-28-2] (21,22), cellulose acetate butyrate sulfate [57485-48-0] (21,22), cellulose acetate propionate sulfate [67351-39-7] (23), and ethylceUulose sulfate (24) are described in the patent Hterature but are not of commercial importance. 

At identification of cognacs and cognac alcohols on authenticity use the following characteristic attributes presence in them significant concentration of (15-150 mg/1) bytanol, the high level of acids - acetic, propionic and oil the high contents of polyphenolic bonds. 

Cellulose nitrate Cellulose acetate Cellulose accetate- hutyrate Cellulose acetate- propionate Cellulose propionate Ethyl cellulose... 

Cellulose acetate-propionate (Tenite Propionate-Kodak) is similar to cellulose propionate. With the shorter side chains, cellulose propionate and cellulose acetate propionate tend to be harder, stiffer and of higher tensile strength than CAB. Like CAB they are easy to vacuum form and also tend to be used for similar applications such as steering wheels, tool handles, safety goggles and blister packs. 

CAP Cellulose acetate propionate PMMA CN Cellulose nitrate... 

If butyric or propionic acids are included in the esterifying mixture, acetate butyrates and acetate propionates are formed. These, requiring less plasticizer, are tougher and more moisture resistant material for making automobile steering wheels. 

Standnikow has prepared several of the esters of menthol by heating magnesium iodo-mentholate with the esters of ethyl alcohol. For example, with ethyl acetate, propionate, and benzoate the corresponding menthyl esters were obtained. These bodies have the following boiling-points —... 

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