醋酸酯淀粉的制备与初步表征

Preparation and Characterization of Acetate Starch

以淀粉为基料,以冰醋酸和醋酸酐为乙酰化试剂,以硫酸为催化剂,制备了醋酸酯淀粉;用红外光谱仪对醋酸酯淀粉进行了初步表征,并用酸碱滴定法测试了其取代度和乙酰基含量;系统讨论了反应温度和反应时间等对醋酸酯淀粉的取代度、乙酰基含量的影响。实验结果表明:随反应温度升高和反应时间延长,乙酰基含量和取代度增大;当反应温度为50℃,反应时间为6h,催化剂质量浓度为0.1%时,取代度和乙酰基含量较高。

Acetate starch was synthesized by using starch as base, the glacial acetate acid and acetic anhydride as acetylating agent, and H2SO4 as catalyst. The chemical structure of the acetate starch was characterized by using IR spectrum. The degree of substitution （DS） and the content of acetyl of the products were determined. The effects of reaction time, reaction temperature on DS and the content of acetyl of the products were discussed. The experiment results showed that DS and the content of acetyl increases with the lengthening of the reaction time and raising of reaction temperature. When the reaction temperature is about 50℃, the reaction time is about 6 hours and the mass concentration of catalyst is about 0. 1（wt）%, the properties of the product is better.