Лако-красочные материалы — производство

White dextrins are produced at low temperatures (120-130°C) and roasting times (3-7 h) in the presence of a high concentration of catalyst. The primary reaction that occurs during the formation of white dextrin is hydrolysis of the starch molecules [9]. This reac­tion initially acts at the 1-6 linkages, and continues with the 1-4 linkages as the concen­tration of 1-6 linkages decreases. Eventually, repolymerization occurs, which yields small, highly branched dextrins. Very little repolymerization occurs in white dextrins, resulting in a white or buff powder with a degree of polymerization of approximately 20. The solubility of the white dextrins can range from 1 to 95% in water, with the lower-solubility grades resembling starch in their characteristics. The higher-solubility grades are more similar to the lower-conversion yellow dextrins. The small amount of repolymerization in the white dextrins makes the suspensions susceptible to retrogradation, and thus the suspensions must be used soon after preparation.