磷酸酯淀粉的制备

选用磷酸氢二钠、磷酸二氢钠、焦磷酸钠及混合磷酸盐作酯化剂制备了木薯磷酸酯淀粉,考察了酯化剂用量、磷酸盐混合物的质量比、尿素等因素对磷酸酯淀粉的取代度和反应效率的影响.结果表明:磷酸酯淀粉的取代度随磷酸盐的用量增加而增大,磷酸盐的结构影响其作用效果.磷酸盐混合物作酯化剂的效果较纯磷酸盐好.添加适量的尿素可提高淀粉的酯化速率和磷酸盐的反应效率.磷酸酯淀粉的取代度对粘度影响不大,但其溶解度是随着取代度的增大而增大.

Preparation of Phosphate Starch

Cassava starch was esterified with sodium acid phosphate, sodium pyrophosphate and the mixture of those phosphates to prepare phosphate starches. The effects of dosages, mass ratios of the phosphates, reaction time and the amounts of urea on the substitution degree of the phosphate starches and reaction efficiency were also investigated. The results showed that the substitution degrees of the phosphate starches increased with increasing the phosphate dosages, and the phosphate structures show significant influence on the reactions. The phosphate mixtures behaved better than any simale phosphate did in the esterification. Urea could remarkably improve the substitution degrees of phosphate starches and the esterification efficiency. The variation of the substitution degrees of phosphate starches did not change the viscosities of the starches significantly, but increased the solubility of the starches.