Abstract: O-substituted chitosan quarternary ammonium salt was synthesized，then aldehydes with different chain lengths were grafted onto the C2 amino group，and O-quarternary ammonium salt -N,N- dialkylated chitosan (QADCS) was obtained. The structure of QADCS was characterized by FTIR， 1H NMR and EA. Meanwhile solubility and surface properties of QADCS were studied. The experimental result indicated that the QADCS can dissolve in chloroform and tetrahydrofuran as N,N-dialkylated chitosan and furthermore，it can dissolve in dimethyformamide and acetic acid，and the contact angle of water on the QADCS film significantly decreased. The hydrophilicity of QADCS was improved obviously and at the same time QADCS could also dissolve in various organic solvents.

摘要： 在合成O-季铵化壳聚糖的基础上，再进行N,N-双烷基化改性，得到O-季铵盐-N,N-双烷基壳聚糖。用FTIR、1H NMR、EA等手段对产物的结构进行表征，并对其溶解性能和表面性能进行研究。实验结果表明：这种新型双亲性壳聚糖季铵盐与N,N-双烷基壳聚糖相比，水的表面接触角降低，亲水性能明显提高；产物除可溶于氯仿与四氢呋喃外，还可溶于N,N-二甲基甲酰胺和冰乙酸中，表现出更明显的双亲性。