壳聚糖的超声波降解

A Research on the Depolymerization of Chitosan by Ultrasonic Wave

目的 利用超声波将非水溶性的大分子壳聚糖降解为水溶性低分子量壳聚糖 ,优选降解的条件。方法 在稀醋酸溶液中 ,超声波的辐射作用下使壳聚糖发生降解。采用粘度测定法 ,探讨了超声波辐射时间与壳聚糖粘度的关系以及壳聚糖的浓度、醋酸的浓度对降解速度的影响。结果 壳聚糖浓度为 1%左右 ,醋酸浓度为 5— 10 % ,降解速度最快 ,辐射 7小时后粘度下降了 73 %。产物经高效液相色谱分析得知 ,随着超声波作用时间的延长低聚糖的含量逐渐增大、分子量也随之降低。 结论

OBJECTIVE Chitosan was depolymerized into water-soluble low-molecular weight polymer by ultrasonic wave and the optimal conditon would be found.METHODS By the means of viscometry, the effects of reaction time, chitosan and acetic acid concentration on the hydrolytic velocity of chitosan by ultrasonic wave were investigated.RESULTS The optimum concentration of chitosan and acetic acid were about 1% and 5～10% respectively and the percentage of reduction of viscosity was 73% after reacting 7 0 hours. The distribution of molecular weight of low molecular chitosan was determined by high performance liquid chromatography method, the result showed that the molecular weight of the depolymerized products decreased and its content rased as increase of prolongation of radiant duration.CONCLUSION Chitosan was depolymerized effectively by ultrasonic wave and water-soluble low molecular chitosan was obtained.