月桂酸淀粉酯在［ BMIM ］ BF4离子液体中的酶法合成

摘要

为了改善淀粉的疏水性能，采用固定化脂肪酶CALB在[ BMIM] BF4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 reac-tion in [BMIM]BF4ionic liquid.Firstly, the structure of modified starch was tested with 1H 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 .