中文摘要：

用γ射线辐照降解制备了低分子量壳聚糖。研究了在H2O2、硼氢化钠、L-α-丙氨酸液中辐照剂量对壳聚糖降解的影响,并对辐照前后壳聚糖的结构进行了表征。结果表明,在H2O2中的壳聚糖降解速率最快,主要是H2O2能够提高·OH自由基浓度,对壳聚糖的降解有促进作用;在硼氢化钠和L-α-丙氨酸水溶液中所降解壳聚糖的白度最佳。样品的UV、FTIR分析表明,辐照后除壳聚糖分子生成羰基外,壳聚糖主链结构未见变化,脱乙酰度也没有显著改变,显示出辐照降解是一种有效的控制壳聚糖分子量的方法。

英文摘要：

The chitosan with low molecular weight was prepared byγ-ray degradation method.The influence of irradiation dose on the radiation degradation of chitosan was studied in heterogeneously aqueous solutions of H2O2,NaBH4and L-α-alanine.The degradation products were characterized by FTIR and UV-VIS.The degradation of chitosan is the most quickly in the H2O2,because of the concentrations of OH radicals increased.The white degree of irradiation degraded chitosan is the highest in NaBH4or L-α-alanine solution.UV and FTIR analyses manifest that no obvious differences in the main chain structure and deacetylation degree between irradiated and un-irradiated chitosans,but the carbonyl group forms in the molecules of the irradiated chitosan.The results show thatγ-ray can be expected as an effective way to control the molecular weight of chitosan.