超声辅助法制备黄姜淀粉醋酸酯及其产物表征

Preparation of yam starch acetates by using ultrasonic-assisted method and characterization of its products

通过比较未施加超声场和超声强化对醋酸酯淀粉取代度的影响,结合扫描电镜(SEM)、X射线衍射(XRD)、热重法(TG)和差热分析(DTA)技术对所制得的黄姜醋酸酯淀粉的形貌,颗粒大小,结晶性及热稳定性进行的表征,探讨超声辅助法制备黄姜淀粉醋酸酯的特点及产物特性。实验结果表明,在制备醋酸酯淀粉的过程中,超声强化可以缩短反应时间,减少催化剂用量。根据SEM、XRD、TG和DTA分析结果说明,超声强化作用引起淀粉降解,破坏了淀粉的非结晶区,增加了乙酰剂与淀粉颗粒的接触位点;对淀粉的结晶区影响甚微,所以超声强化对产品的热稳定性影响较小。

The feature of ultrasound on estedfication of yam starch were investigated by comparing the effects of ultrasound with preparation without ultrasound on the degree of substitution of yam starch acetates. In addition, the influences of ultrasonic wave on the particle shape, particle size, crystallinity and thermostability of yam starch acetates were analyzed by means of SEM, XRD, TG and DTA. The results of research showed that： the enhancement effects of ultrasound on esterification of yam starch can shorten the reaction time, and decrease the amount of catalyst. The results of XRD, SEM, TG and DTA showed that： the ultrasound can degrade the yam starch, and damage the crystallinity of yam starch acetates. The reactive area between yam starch and acetylating agent can increased with enhancement effects of ultrasound. The influences of ultrasound on the crystallinity of yam starch acetates are feeble, so the ultrasound has little influence on the thermostability of yam starch acetates.