微波水热法降解壳聚糖的研究

Microwave Hydrothermal Degradation of Chitosan

在H_2O_2和α-淀粉酶存在的条件下,使用微波水热法,在低浓度醋酸溶液中快速降解壳聚糖。研究了醋酸浓度、H_2O_2和α-淀粉酶用量以及微波水热时间对壳聚糖降解的影响,并利用FTIR对降解的壳聚糖进行了分析。结果显示,在V(H_2O_2):m(壳聚糖)=2mL/g,m(壳聚糖):m(α-淀粉酶)=3的条件下,40℃微波水热反应40min,即可使壳聚糖粘均分子量下降99.8%以上,而用普通水热法达到相同分子量则需约9h,微波水热法大大提高了降解壳聚糖的效率,同时不破坏壳聚糖本身的结构,是一种高效环保的壳聚糖降解方法。

A novel method of degradation of chitosan was investigated by using microwave hydrothermal method in the presence of H2O2andα-amylase with dilute acetic acid solution as solvent.The effects of the concentration of acetic acid,the dosage of H2O2andα-amylase,and the time of microwave hydrothermal on the degradation of chitosan were evaluated.And the structure of the degraded product was characterized by FTIR（Fourier Transform Infrared Spectroscopy）.The results show that with the microwave hydrothermal method,the viscosity-average molecular weight of chitosan can decrease by more than 99.8% after 40minutes’ reaction at 40℃ under the condition of V（H2O2）：m（chitosan）=2mL/g and m（chitosan）：m（α-amylase）=3,while it takes 9hours to get the same degree of degradation with the traditional hydrothermal method.Therefore,the microwave hydrothermal method,which greatly improves the efficiency of the degradation of chitosan without changing the main macromolecular structure of chitosan,is a high efficient and environmentally friendly degradation method.