Pressure pretreatment for improving the acetylation of cellulose

Details Pressure pretreatment for improving the acetylation of cellulose Pressure pretreatment for improving the acetylation of cellulose

1993-02-12

1994-12-06

Nutter, Nathan M.

Organic compounds -- part of the class 532-570 series

Organic compounds

Carbohydrates or derivatives

536 59, 536 63, 536 69, 536 70, 536 71, C08B 306, C08B 102

Patent

active

053712072

ABSTRACT:
A novel method has been discovered for the pretreatment of cellulose with acetic acid and acetic anhydride under pressure, resulting in uniformly activated cellulose fibers. The improved process for producing cellulose diacetate comprises the steps of: (1) pretreating and activating the fluffed cellulose fibers in a solution of glacial acetic acid and acetic anhydride at room temperature and elevated pressure for a specific time; (2) mixing the activated cellulose containing acetic acid and anhydride further with a mixture of glacial acetic acid, acetic anhydride and sulphuric acid catalyst and acetylating the cellulose at specific initial and end temperatures to form primary cellulose acetate; and (3) partially neutralizing the sulphuric acid catalyst and destroying the excess acetic anhydride by adding an aqueous solution of magnesium acetate with dilute acetic acid to provide an excess of water in the reaction dope for hydrolysis at elevated temperature and pressure conditions.

REFERENCES:
patent: 2854446 (1958-09-01), Robin
patent: 2923706 (1960-02-01), Campbell et al.
patent: 3631023 (1971-12-01), Horne et al.
patent: 3755297 (1973-08-01), Campbell et al.
patent: 3767642 (1973-10-01), Campbell et al.
patent: 3870703 (1975-03-01), Gibney et al.
patent: 4016353 (1977-04-01), Goheen et al.
patent: 4269972 (1981-05-01), Yabune et al.
patent: 4306060 (1981-12-01), Ikemoto et al.
patent: 4439605 (1984-03-01), Yabune et al.
Grant & Hackh's Chemical Dictionary McGraw-Hill Book Company New York 1987 p. 578.

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