【作者】 杨建洲； 胡林； 吴华；

【Author】 YANG Jian-zhou,HU Lin,WU Hua (College of Chemistry and Chemical Engineering,Shaanxi Universityof Science & Technology,Xianyang 712081,China)

【机构】 陕西科技大学化学化工学院；

【摘要】 以玉米淀粉为原料,以醋酸乙烯酯为酰化剂,研究得到制备醋酸酯淀粉的最佳反应条件为:m(淀粉):m(醋酸乙烯酯)=10:1,pH值9～10,反应温度24℃,反应1h,得到的产物乙酰基含量2.33%,取代度0.090,反应效率47.7%。以醋酸酐为酰化剂,在碱性条件下反应制备低取代度的醋酸酯淀粉,研究得到最佳反应条件:m(淀粉):m(醋酸酐)=10:1.5,pH值8.0～8.4,反应温度20～25℃,反应3h,得到的产物乙酰基含量1.93%,取代度0.074,反应效率31.1%。尝试在不同反应介质和不同反应条件下反应制备高取代度醋酸酯淀粉,研究得到在吡啶中反应取代度最高,得到的产物乙酰基含量16.90%,取代度0.763,反应效率15.0%。更多还原

【Abstract】 In this paper we described the manufacture of acetic ester of starch with the corn starch and the ethylene ester of acetic acid as the agent of acylation.The optimum conditions were:m(starch):m(ethylene ester of acetic acid)=10:1,pH is 9～10,reaction temperature is 24℃,reaction time is 1h,the content of base of acety is 2.33%.Degree of substitution is 0.090, reaction efficiency is 47.7%.We got the lower degree of substitution of acetic ester of starch when we used acetic anhydride as the agent of acylation.The optimum conditions were:m(starch):m(acetic anhydride)=10:1.5,pH is 8.0～8.4,reaction temperature is 25～30℃,reaction time is 3h,the content of base of acety is 1.93%.Degree of substitution is 0.074,reaction efficiency is 31.1%.We tried to prepare the high degree of substitution in different conditions and found that the degree of substitution was higher in pyridine. The results were:content of base of acety is 16.90%,degree of substitution is 0.763,reaction efficiency is 15.0%.更多还原