Esters manufacture following

This suggests that cellulose esters may be manufactured following a simplified esterification protocol in which steam exploded fibers are subjected to chemical modification followed by an optional separation of lignin at the end of the esterification procedure (Figure 8). The protocol is capable of generating an impure wood ester product with engineerable thermoplastic properties, or it may conversely be used to prepare a pure cellulose ester product, cleanly separated from a lignin ester polymer by appropriate solvent precipitation. 

Reduction. Hydrogenation of dimethyl adipate over Raney-promoted copper chromite at 200°C and 10 MPa produces 1,6-hexanediol [629-11-8], an important chemical intermediate (32). Promoted cobalt catalysts (33) and nickel catalysts (34) are examples of other patented processes for this reaction. An eadier process, which is no longer in use, for the manufacture of the 1,6-hexanediamine from adipic acid involved hydrogenation of the acid (as its ester) to the diol, followed by ammonolysis to the diamine (35). 

Manufacture and Uses. Acetoacetic esters are generally made from diketene and the corresponding alcohol as a solvent ia the presence of a catalyst. In the case of Hquid alcohols, manufacturiag is carried out by continuous reaction ia a tubular reactor with carefully adjusted feeds of diketene, alcohol, and catalyst, or alcohol—catalyst blend followed by continuous purification (Fig. 3). For soHd alcohols, an iaert solvent is used. Catalysts used iaclude strong acids, tertiary amines, salts such as sodium acetate [127-09-3], organophosphoms compounds, and organometaHic compounds (5). 

Manufacture. Cyanoacetic acid and cyanoacetates are iadustrially produced by the same route as the malonates starting from a sodium chloroacetate solution via a sodium cyanoacetate solution. Cyanoacetic acid is obtained by acidification of the sodium cyanoacetate solution followed by organic solvent extraction and evaporation. Cyanoacetates are obtained by acidification of the sodium cyanoacetate solution and subsequent esterification with the water formed being distilled off. Other processes reported ia the Hterature iavolve the oxidation of partially oxidized propionittile [107-12-0] (59). Higher esters of cyanoacetic acid are usually made through transesterification of methyl cyanoacetate ia the presence of alumiaiumisopropoxide [555-31-7] as a catalyst (60). 

Seb cic Acid. Sebacic acid [111-20-6] C QH gO, is an important intermediate in the manufacture of polyamide resins (see Polyamides). It has an estimated demand worldwide of approximately 20,000 t/yr. The alkaline hydrolysis of castor oil (qv), which historically has shown some wide fluctuations in price, is the conventional method of preparation. Because of these price fluctuations, there have been years of considerable interest in an electrochemical route to sebacic acid based on adipic acid [124-04-9] (qv) as the starting material. The electrochemical step involves the Kolbn-type or Brown-Walker reaction where anodic coupling of the monomethyl ester of adipic acid forms dimethyl sebacate [106-79-6]. The three steps in the reaction sequence from adipic acid to sebacic acid are as follows ... 

As shown in the introductory section to this chapter, polyesters may be produced in many ways, one of which is the method of ester exchange. This has been of importance in the manufacture of linear polyesters for a number of reasons which include the following ... 

In the manufacture of geranyl acetate on a commercial scale it would not pay to make it absolutely pure, so that samples as met with in the ordinary way are not quite pure geranyl acetate. The acetylisation process, by which esters are made, is not always a quantitative one, and in some cases it is impossible to acetylate an alcohol to its full theoretical extent. Commercial samples, however, contain 95 per cent, or more of true ester, and should have the following characters —... 

For the manufacturing of sulfosuccinic acid esters, which belong to a special class of surfactants, maleic acid anhydride is needed. Maleic acid anhydride is an important intermediate chemical of the chemical industry. Its worldwide output amounts to about 800,000 tons (1990) [64]. Maleic acid is produced by catalytic vapor phase oxidation process of benzene or n-C4 hydrocarbons in fixed bed or fluidized bed reactors according the following reaction equations. The heat of reaction of the exothermic oxidation processes is very high. 

Although Lhe first cellulose plastic (cellulose nitrate plastic-based on an inorganic ester of cellulose) was developed in 1865. the first organic cellulose ester plastic was not offered commercially until 1927. In that year, cellulose acetate plastic became available as sheets, rods, and tubes. Two years later, in 1929. it was offered in the form of granules for molding. It was the first thermoplastic sufficiently stable to be melted without excessive decomposition, and it was the first thermoplastic to be injection molded. Cellulose acetate butyrate plastic became a commercial product in 1938 and cellulose propionate plastic followed in 1945. The latter material was withdrawn after a short time because of manufacturing difficulties, but it reappeared and became firmly established in 1955. 

Pimetic Acid. This acid is manufactured by Tateyama Chemical Company in Japan in quantities of about 100(1-200(1 kg/yr. and by Heinrich Mock Nachf in Germany. The method or process they are using lias not been disclosed. Pimelic acid is available in small quantities with purities of 98% from laboratory chemical supply companies. The preparation of pimelic acid has been described in Organic Syntheses cyclohexanone condenses with diethyl oxalate, followed by decarboxylation in ethyl 2-keto-hcxahydmhcnzoatc, and then eleavage of the fl-keto ester with strong alkali. 

Lyophilized and dry samples should be reconstituted with water prior to extraction. They may require saponification if the samples contain chlorophylls or xanthophyll esters. Beadlet materials should be suspended in hot water, saponified, or enzymatically hydrolyzed before extraction. Follow the manufacturer s recommendations before analyzing by HPLC. 

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