超声作用下辛烯基琥珀酸淀粉酯合成工艺及反应机理研究

以木薯淀粉为原料,辛烯基琥珀酸酐为变性剂,采用湿法工艺,在超声作用下制备辛烯基琥珀酸淀粉酯.用单因素实验探索最佳制备工艺条件及酯化反应机理.结果表明,超声作用制备辛烯基琥珀酸淀粉酯的最佳工艺条件为：超声作用时间30 min,超声功率250 W,酯化pH 8.5,反应温度35℃,在最佳工艺条件下制备所得辛烯基琥珀酸淀粉酯取代度达0.0181,比未施加超声作用所制得的产品取代度提高了28.4％.超声波强化淀粉变性反应机理是超声波的空化效应对木薯淀粉的颗粒结构有一定影响,使淀粉颗粒表面变粗糙,增加了反应物之间的接触面积,强化了酯化反应的发生.

Synthesis Process and Reaction Mechanism of Octenyl Succinic Anhydride Modified Starch under Ultrasonic Irradiation

The octenyl succinic anhydride modified starch （OSAS） was prepared with the cassava starch as raw material, octenyl succinic anhydride （OSA） as denaturant via a wet process under ultrasonic irradiation. The optimal preparation process and the esterification modified reaction mechanism were explored by single factor experiments. The results show that the conditions of the optimum preparation process of OSAS under ultrasonic： ultrasonic action time 30 rain, ultrasonic power 25（I w, the esterification pH 8.5, the reaction temperature 35 ~C. The degree of substitution （DS） of the OSAS is 0.0181 under the condition of optimum preparation process, increasing 28.4 % when compared with not applied ultrasound. The mechanism of ultrasonic strengthening starch modified reaction is that ultrasonic cavitation has effect on granule structure of cassava starch. The starch granule surface is becoming roughness, the contact area between the reactants increase and the esterification reaction strengthen.