Verfahren zur Herstellung von Polysaccharidestern oder Polysaccharidmischestern

DE 102009022805 A1 UPAB: 20101216 NOVELTY - Producing polysaccharide ester or polysaccharide mixed ester, comprises reacting a polysaccharide or a modified polysaccharide with at least one esterification reagent comprising carboxylic acid, carboxylic acid anhydride, carboxylic acid halide and/or carboxylic acid ester and at least one halide component comprising carboxylic acid halide, halide ether, alkyl halide, halo carboxylic acid and/or hydrogen halide, where the esterification is carried out in presence of at least one in-situ generated imidazole compound (I). DETAILED DESCRIPTION - Producing polysaccharide ester or polysaccharide mixed ester, comprises reacting a polysaccharide or a modified polysaccharide with at least one esterification reagent comprising carboxylic acid, carboxylic acid anhydride, carboxylic acid halide and/or carboxylic acid ester and at least one halide component comprising carboxylic acid halide, halide ether, alkyl halide, halo carboxylic acid and/or hydrogen halide, where the esterification is carried out in presence of at least one in-situ generated imidazole compound of formula (I). R, R1, R2, R3 = 1-12C alkyl, 2-12C alkenyl or 2-12C alkynyl, which optionally exhibits further functional groups comprising carbonyl-, nitro-, halide-, thiol- and ether functionality, and primary, secondary and tertiary amine; and X- = counterion. USE - The polysaccharide ester or polysaccharide mixed ester, preferably starch acetate and starch propionate are useful as fibers and synthetic materials in food industry. ADVANTAGE - The method: is fast; exhibits simple process execution; and requires moderate reaction temperature and short reaction time and thus the method is economical