N-酰基壳聚糖的制备及取代度控制的研究

对壳聚糖于醋酸／甲醇介质中的N-乙酰、N-丙酰、N-丁酰、N-己酰化反应进行了研究．结果表明：壳聚糖的N-酰基化反应在室温1h内接近完全，N-酰基取代度(Ds)取决于醋酸和甲醇浓度以及酸酐与氨基的摩尔比(R)，对醋酸和甲醇浓度及酸酐与氨基摩尔比进行控制，可制得不同取代度的N-酰基壳聚糖，较为合适的反应条件为：MeOH浓度80％(w／w)、AcOH浓度1％(w／w)、酸酐与氨基摩尔比O～3．

Studies on the Proparation and Controlled Degree of Substitute for N-acylchitosan

N\|Acylation of chitosan with different carboxylic anhydrides such as acetic, propionic, butyric, and hexanoic anhydride in the mediums of acetic acid and methanol solutions were studied. It's concluded that the N\|acylation was fast reaction, and the degrees of N\|acylation were mainly dependent on the concentrations of methanol, acetic acid in the solution as well as the mole ratio of carboxylic anhyclrides to amino group. By adjusting these factors, chitosan with different N\|acylation degree could be prepared successfully, the propriate condition is recommended as follows; MeOH, 80%( w/w ); AcOH, 1%( w/w ), the mole ratio of carboxylic anhydride to amino group ranging from 0 to 3.