壳聚糖N-烷基化改性反应影响因素的研究

Study on effects of reaction conditions on N-acetylation of chitosan

以取代度及特性粘度为指标,研究了反应时间、反应温度、醛及NaBH4的用量等对壳聚糖的N-烷基化反应的影响。结果表明,反应时间对产物的取代度和特性粘度有较大的影响。要得到高粘度、高取代度的衍生物,反应时间以20～24h为宜。为了制备高取代度和高粘度的衍生物,反应温度不超过40℃为宜。醛的用量应为壳聚糖所含-NH2的物质的量的4～5倍较适。NaBH4加入量为壳聚糖所含-NH2的6倍为适。

Using substitution degree and characteristic viscosity as the indexes, the conditions of Chitosan N-acetylation were researched, such as reaction time, reaction temperature, dosage of aldehyde and NaBH4. The results showed that reaction time and reaction temperature influenced the degree of substitution and characteristic viscosity greatly, and in order to get high substitution degree and characteristic viscosity, the optimal condition was： reaction time is 20-24h, reaction temperature is 40℃, the dose of aldehyde and NaBH4 is respectively 4-5 and 6 times of that of -NH2 contained in chitosan.