论文部分内容阅读
以高脱乙酰化的壳聚糖为主要原料 ,在乙酸水溶液 -乙醇 -吡啶介质中 ,实现了壳聚糖的 N位均相乙酰化反应 ,制备了脱乙酰度为 5 0 %左右 ,在 p H=1～ 14范围内具有良好水溶性的壳聚糖。重点考察了乙酸酐用量对脱乙酰度的影响 ,结果表明 ,当乙酸酐用量与壳聚糖的摩尔比在 2 .0左右时 ,产物的脱乙酰度接近 5 0 % .通过对所用的高脱乙酰度壳聚糖特性粘度 [η]的测定 ,间接得到了产物的分子量为 1.66×10 5左右。对产物进行了 FT- IR及 1H- NMR表征 ,谱图中与乙酰胺基有关的信号均发生了变化 ,表明了乙酰化反应的发生。
Using highly deacetylated chitosan as the main raw material, homogeneous N-acetylation of chitosan was achieved in aqueous acetic acid-ethanol-pyridine, and the degree of deacetylation was about 50% H = 1 ~ 14 range of good water-soluble chitosan. The effect of the amount of acetic anhydride on the degree of deacetylation was investigated. The results showed that when the molar ratio of acetic anhydride to chitosan was about 2.0, the degree of deacetylation was close to 50% .At the same time, The determination of the intrinsic viscosity [η] of acetyl chitosan indirectly gives the product a molecular weight of about 1.66 × 10 5. The products were characterized by FT-IR and 1H-NMR. The signals related to acetamidase changed in the spectrum, indicating the acetylation reaction.