GB356665A - - Google Patents

Abstract

Carboxylates.-Mixed carbohydrate esters are formed by treating the carbohydrate or a conversion product thereof with a quantity of fatty acid anhydride calculated for the formation of triacidylate in combination with a quantity of a fatty acid different from that corresponding with the anhydride, with or without a catalyst. The products may be hydrolyzed in known manner. The reaction may be carried out in the presence of acetic acid, propionic acid, benzene or the like as a diluent. In examples, (1) a cellulose acetobutyrate is produced by introducing 100 parts of cellulose into a mixture of 100 parts acetic anhydride, 100 parts butyric acid, 600 parts liquid sulphur dioxide and 12 parts of sulphuric acid at a temperature of 18-23 DEG C., followed by addition of 85-90 parts acetic anhydride and completion of the esterification at 23-24 DEG C.; hydrolysis is effected by a mixture of 100 parts 30 per cent butyric acid and 3 parts sulphuric acid: (2) a cellulose butyropropionate is obtained by treating 100 parts cellulose at 40 DEG C. with 245-250 parts of propionic anhydride, 400 parts of butyric acid and 100 parts of zinc chloride: (3) a starch acetobutyrate is obtained by treating 100 parts of starch with 185 parts of acetic anhydride, 150 parts of butyric acid, 400-600 parts of benzene and 3 parts of sulphuric acid in a rotating drum at 40-60 DEG C.; the product is isolated by centrifuging and washed with water and dried; it is soluble in acetone.