PREPARATION AND CHARACTERIZATION OF STARCH ACETATE

Acetylation of native hydrolyzed and oxidized, maize starch has been s tudied. The different factors affecting acetylation process were inves tigated. These factors include liquor ratio, acetic anhydride, perchlo ric acid concentration, reaction time and temperature. Also investigat ed were characterization and application of the acetylated starches in textile warp sizing. The acetyl content increases to reach a maximum and then decreases on increasing either liquor ratio or perchloric aci d concentration. Also it increases with increasing acetic anhydride co ncentration within the range examined whereas the acetylation reaction efficiency % decreases. Hydrolysis of starch prior acetylation inhanc es the susceptibility of the starch towards acetylation whereas oxidat ion do the reverse. The solubility of acetylated starches derived from hydrolyzed or oxidized starches increases more than that of acetylate d native starch. The solubility depends on the extent of acetylation a nd of the modification prior acetylation. Acetylation of starch improv es its sizeability of cotton yarns.