摘要
采用氢氧化钠催化、用醋酸酐干法酯化玉米淀粉,制备了低、中、高3种取代度的淀粉醋酸酯,通过羧基含量的变化研究了酯化改性的反应动力学,并以FTIR和XRD分析了改性淀粉的结构特征。结果表明,淀粉的醋酸酐酯化反应符合二级反应动力学,在催化下其活化能为36.16 k J/mol;酯化后淀粉缔合羟基数量锐减,而羰基和酯基逐渐增多;随取代度提高,淀粉的结晶度降低。
Esterified starch samples with low, moderate and high levels of substitution degrees （DS） were prepared in dry-state with acetic anhydride by using NaOH as catalyst. FTIR and XRD were applied to detect the changes of starch structure after the modifica- tion. The results showed that the associated hydroxyl groups in starch declined sharply, but the earbonyl group and ester group grew gradually with the increase of DS. The crystallinity in starch granule was decreased along with the modification. Changes of carboxyl group content during the modification demonstrated that the esterification of starch fitted the characteristic of second-order reaction ki- netics. The reaction activation energy was 36. 16 kJ/mol.
出处
《四川大学学报（工程科学版）》
EI
CAS
CSCD
北大核心
2015年第5期191-195,共5页
Journal of Sichuan University (Engineering Science Edition)
基金
国家"863"计划资助项目(2007AA03Z344)
四川大学青年教师科研启动基金项目(2014SCU11030)
关键词
醋酸酐
玉米淀粉
干法
酯化
acetic anhydride
corn starch
dry method
esterification
