Properties of Hemicellulose/Chitosan Composite Prepared in Ionic Liquid System

摘要

The application of chitosan in some fields is limited due to its low antioxidant property and difficulty to dissolve in water.In this paper,the hemicellulose/chitosan composite was prepared in ionic liquid system using glutaraldehyde as crosslinking agent.The antioxidant activity,reducing capacity and the metal ion chelating ability of the resulted composite materials were determined.The chemical structure and thermal stability were analyzed by FT-IR,XRD and TGA.The results showed that the chitosan was successfully cross-linked with hemicellulose by glutaraldehyde in ionic liquid system.Compared to the pure chitosan,the scavenging ABTS·+activity of the hemicellulose/chitosan composite increased from 10.56％to 97.59％.After cross-linked with hemicellulose by glutaraldehyde,the reducing power of the chitosan increased from 0.054 to 2.109.The metal ion chelating power of composite also increased from 42.35％to 86.71％compared to that of pure chitosan.The crystalline region of chitosan was destroyed due to the introduction of hemicellulose and the thermal stability of the composite decreased.The cross-linking of hemicellulose to chitosan not only improve the antioxidant activity,reducing power and metal ion chelating ability of pure chitosan,but also provide a new idea for the high value utilization of hemicellulose.It has potential in preparing the green packaging materials.