微波辅助改性壳聚糖的制备及其絮凝性能

以壳聚糖、阳离子醚化剂二甲基二烯丙基氯化铵为原材料，采用微波辐射的方法，制备了壳聚糖接枝共聚物（壳聚糖-二甲基二烯丙基氯化铵），并通过红外光谱分析对改性壳聚糖进行了表征。以接枝率为标准，确定改性壳聚糖的最佳反应条件，并以高岭土悬浊液和实际生活污水作为处理对象，测定了改性壳聚糖的絮凝性能。结果表明，壳聚糖接枝共聚物的最佳制备条件是微波反应温度55℃，反应时间20 min，壳聚糖0.5 g，微波功率270 W，阳离子醚化剂的浓度20%，在此条件下，合成的改性壳聚糖的接枝率为80%。红外光谱分析结果显示，已成功地合成了壳聚糖-二甲基二烯丙基氯化铵接枝共聚物。在絮凝实验中，壳聚糖接枝共聚物的去浊率最高达到91%，COD去除率最高达到77%。其结果表明，壳聚糖接枝共聚物的絮凝性能明显高于原料壳聚糖。

Microwave-assisted modified chitosan and flocculation property

A chitosan-grafted copolymer (chitosan-DMDAAC) was prepared from chitosan and dimethyl diallyl ammonium chloride (DMDAAC) using a microwave irradiation method, and the modified chitosan was characterized via infrared spectroscopy. The optimal reaction conditions of modified chitosan were studied to find the highest graft rate, and its flocculation capability was tested using processing kaolin suspensions and actual domestic wastewater. The results showed that, under the optimal reaction conditions (microwave reaction temperature of 55℃, microwave reaction time of 20 min, 0.5 g of chitosan, microwave power of 270 W, 20% DMDAAC concentration), the graft rate of modified chitosan was 80%. Fourier-transform infrared analysis results showed that the chitosan-DMDAAC graft copolymer was successfully synthesized. In flocculation experiments, the turbidity removal efficiency of the chitosan-DMDAAC graft copolymer reached 91%, and its chemical oxygen demand (COD) removal efficiency reached 77%. The results indicate that the chitosan-grafted copolymer (chitosan-DMDAAC) has better flocculation properties than chitosan.