月桂酸淀粉酯在[BMIM]BF_4离子液体中的酶法合成

Synthesis of laurate starch through lipase-catalyzed reaction in [BMIM]BF_4 ionic liquid

为了改善淀粉的疏水性能,采用固定化脂肪酶CALB在[BMIM]BF_4离子液体中对淀粉进行了月桂酸酯化改性。首先,对反应后得到的产物结构进行了核磁分析,结果显示月桂酸在脂肪酶的催化作用下成功对淀粉进行了改性。其次,研究了不同因素对产物取代度的影响,结果表明月桂酸淀粉酯的较优制备条件为:脂肪酶用量0.2 g、月桂酸/AGU摩尔比=3∶1、反应温度60℃、反应时间4 h。最后,对月桂酸接枝后淀粉的疏水性能进行了测试,结果显示淀粉的润湿接触角明显提高,而且随着取代度的增加,疏水性也越高。

In order to improve the hydrophobilicity of raw starch,lauric acid was grafted on starch through CALB lipase-catalyzed reaction in [BMIM]BF_4ionic liquid. Firstly,the structure of modified starch was tested with1 H NMR,it showed that the lauric acid was successfully grafted on starch. Secondly,the effect of different reaction conditions on the DS values of modified starch was studied in detail. Results showed that a better synthesis condition for laurate starch was as follows： lipase dosage 0. 2 g,lauric acid / AGU = 3： 1,temperature 60℃,time 4 h. Finally,the hydrophobilicity of modified starch was tested through water contact angle. Results showed that the hydrophobicity of modified starch was significantly improved and increased with DS values.