高取代度淀粉醋酸酯合成工艺优化及结构表征

以玉米淀粉为实验材料，在催化剂用量、醋酸与醋酸酐体积比、反应时间、反应温度4个单因素试验基础上，利用响应面试验设计法进行试验设计，获得取代度与各单因素的函数关系，并建立高取代度淀粉醋酸酯合成工艺模型。通过回归方程和响应曲面，得到淀粉醋酸酯最佳合成工艺为催化剂用量0.11mL、醋酸与醋酸酐体积比1:1.39、反应时间1.59h、反应温度87.61℃。验证实验结果显示，在此条件下淀粉醋酸酯取代度为2.95。傅里叶红外光谱分析表明，淀粉醋酸酯葡萄糖单元上的羟基逐渐发生酯化，而且随着取代度测定值升高，乙酰基含量增大。扫描电镜照片显示，淀粉醋酸酯表面变得更为粗糙，孔隙增多且呈蜂窝状，说明酯化反应不仅发生在淀粉颗粒表面，同时也发生在淀粉颗粒内部。

Highly Substituted Starch Acetate:Optimization of Synthesis Process and Structural Characterization

To optimize the process for the synthesis of starch acetate from corn starch,the effects of catalyst amount,the volume mixing ratio of acetic acid to acetic anhydride,and reaction time and temperature on the degree of substitution (DS) of starch were evaluation by single factor experiments,and a mathematical model describing the functional relationship between starch DS and the above four variables was set up based on a 29-run,4-factor,3-level response surface design coupled with multiple regression fitting...