机械活化玉米淀粉的辛烯基琥珀酸酐酯化改性

Synthesis of Octenyl Succinic Esters of Mechanically Activated Corn Starch

采用行星式球磨机对玉米淀粉进行机械活化,再与辛烯基琥珀酸酐(octenyl succinic anhydride,OSA)发生酯化反应制备OSA淀粉酯。研究机械活化时间、反应温度、反应体系pH值、淀粉乳质量分数、反应时间因素对玉米淀粉酯化反应的影响,并采用二次回归正交旋转组合设计方法和响应面分析对制备条件进行优化。结果表明,机械活化对玉米淀粉OSA酯化反应有明显的增强作用,且反应不受pH值的影响;得到最优工艺条件为机械活化10 h、反应温度33.1℃、pH 8.45、淀粉乳质量分数12.2%、反应时间3 h,在此条件下制得机械活化辛烯基琥珀酸淀粉酯的平均取代度为0.020 3。

Corn starch was mechanically activated by ball milling(rolling-type) and then esterified by octenyl succinic anhydride(OSA) in aqueous slurry systems. The process of esterification was studied with respect to the time of mechanical activation, reaction temperature, p H, starch slurry concentration and reaction time. The optimum reaction conditions were determined by the quadratic regression orthogonal rotation design and response surface methodology. The results indicated that the mechanical activation considerably enhanced the esterification of corn starch and the esterification showed a low sensitivity to pH changes. The optimum reaction conditions were determined as follows: mechanical activation time, 10 h; the concentration of activated starch, 12.2%; reaction temperature, 33.1℃, reaction system p H, 8.45; and reaction time, 3 h. Under these conditions, the degree of substitution of mechanical activation starch obtained was 0.020 3.