Cellulose esters manufacture following

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 The latter material was withdrawn after a short time because of manufacturing difficulties, but it reappeared and became firmly established in 1955. 

Other cellulose esters of organic acids, including those of substituted and polybasic acids, have been studied in detail and will be described in sections to follow. Their cost of manufacture is in general greater than that of the more simple esters, and their uses are confined to cases in which special properties are required. 

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. 

The vapors of the organic solvents used in the preparation of cellulose ester solutions represent a potential fire, explosion, or health hazard. Care should be taken to provide adequate ventilation to keep solvent vapor concentrations below the explosive limits. Mixing equipment should be designed to ensure that solvent temperatures do not approach their flash point during the mixing cycle. All equipment must be electrically grounded to prevent static discharge, and appropriate precautions should be followed as recommended by the manufacturer of the solvents. 

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