Research On The Modifcation Of Chitosca

Firstly, water solubility of the chitosan was improved by methoxy poly(ethylene glycol)(mPEG) in this paper. mPEG with different molecular weights after carboxylated was occurred esterification reaction to the hydroxyl groups at C-3 on the chitosan backbone, and the comb-shaped methoxy poly(ethylene glycol) grafted chitosan(CS-g-mPEG) which can be dispersed in water was prepared. The structure of CS-g-mPEG was characterized by infrared spectroscopy (IR) and nuclear magnetic resonance('H-NMR), and the results showed that CS-g-mPEG can be successfully prepared by this method. Water-soluble experiment of the graft copolymer showed that the solubility of the CS-g-mPEG graft copolymer was improved significantly.polylactide(PLA) was introduced to chitosan, and the graft copolymer of chitosan-g-polylactide(CS-g-PLA) was synthesized successfully through ringopening polymerization by the hydroxyl group of the chitosan initiated, in order to improve fat solubility. The structure of this graft copolymer was characterized by IR and 1H-NMR. Fat-soluble experiment of the copolymer showed that chitosan grafted PLA can dissolve in partial organic solvents.In addition, in this paper, the free amino was introducd to the surface of the PLA membrane by using aminolysis technique, and amino group was transformed into adehyde group by using glutaraldehyde, then chitosan-modified PLA membrane was fabricated by chitosan-coating technique. The structure of the modified PLA was characterized by IR. The results showed that chitosan can be successfully fixed in the surface of the polylactide membrane. The biocompatibility of PLA can be improved after chitosan grafted the surface of PLA membrane.