过氧化氢降解壳聚糖制备壳聚糖低聚体的工艺研究

Study on the Preparation of Chitosan Oligomer through the Chitosan Degraded by Hydrogen Peroxide

[目的]以天然资源壳聚糖为原料,进行了过氧化氢降解壳聚糖制备壳聚糖低聚体的研究,为壳聚糖低聚体的工业化生产提供参考。[方法]在中性条件下,分别对影响壳聚糖降解的因素壳聚糖质量分数、过氧化氢与壳聚糖物质的量比、反应时间和反应温度进行了优选试验,采用凝胶渗透色谱测定了分子量,采用红外光谱确定了其结构。[结果]建立了较理想的水解工艺:壳聚糖的质量分数为12%,反应温度为70℃,反应时间为6h,n(过氧化氢):n(壳聚糖)=4,此条件下的壳聚糖低聚体收率为73.0%。壳聚糖低聚体的数均分子量为1798.1,重均分子量为2986.6,分子量分散度为1.66。经红外光谱分析,制备的低聚壳聚糖与其原料壳聚糖结构一致。[结论]采用过氧化氢降解壳聚糖制备壳聚糖低聚体工艺简单、实用,所用生产原料少,无三废,可积极推广。

[Objective]The reference for the industrial production of chitosan oligomer was provided through the experiment in its preparation of the natural chitosan,as raw material,degraded by hydrogen peroxide.[Method] The factor affecting the chitosan-degrading such as its mass fraction,the mole rate of hydrogen peroxide to chitosan,the reaction temperature and time was optimized under the neutral condition.The molecular weight was measured with the method of gel permeation chromatograph and the structure was analyzed with IR spectrum analyzer.[Result]The idea hydrolyzation technology was established,under which condition of the mass fraction of chitosan：12%,the reaction temperature：60 ℃,the reaction time：6 hours,the mole rate of hydrogen peroxide to chitosan：4,the yield of chitosan oligomer was 73.0%.The averaged molecular weight of it was 1 798.1,the mean molecular weight was 2 986.6 and the dispersion degree of molecular weight was 1.66.Characterized by IR spectrum analysis,it was known that the structure of chitosan oligomer was same as the chitosan as raw material.[Conclusion]The technology was simple,practical,less consumption of raw material,non-pollution,which could be actively extended and used.