以木薯淀粉为原料,柠檬酸为酯化剂,以自制的高能效搅拌球磨机为固相反应器制备淀粉柠檬酸酯。分别研究了反应时间、反应温度、柠檬酸用量等因素对酯化淀粉取代度的影响,并采用红外光谱仪对酯化淀粉结构进行分析。结果表明,在反应时间60 min、反应温度50℃、柠檬酸占淀粉用量40%、氢氧化钠占淀粉用量4%条件下,可制备取代度为0.148的淀粉柠檬酸酯。红外光谱表明改性淀粉出现酯化特征吸收峰,说明淀粉已经成功酯化。
Starch citrate was prepared by solid phase reaction in a home-made high efficiency stirring ball mill using cassava starch as material and citric acid as esterifying agent. The effects of reaction time, reaction temperature, citric acid dosage, etc. on the degree of substitution(DS) of products were investigated, and the structure of products was analyzed by Fourier transform infrared spectroscopy(FTIR). The results showed that the starch citrate with DS of 0.148 was prepared under the conditions of reaction time 60 min, reaction temperature 50 ℃, citric acid dosage 40%, and sodium hydroxide dosage 4%. FTIR spectra of the products presented characteristic absorption peak of ester group, indicating that the esterification reaction successfully took place between starch and citric acid.