| Summary: | 碩士 === 淡江大學 === 化學工程與材料工程學系碩士班 === 93 === In this study, chitosan was dissolved in formic acid and modified with phthalic anhydride in N,N-dimethylformamide (DMF), through the reaction of amino group with anhydride group. In this way, chitosan can be dissolved in organic solvent. The results show that the degree of substitution increased with reaction time. In addition, the modified chitosan could be dissolved in several organic solvents, such as DMF、DMAc and DMSO. After reaction, the available hydroxyl group in the chitosan was used to graft synthetic polymers onto chitosan chains with poly(ethylene glycol) diglycidyl ether. Photoinitiator (UVI-6992) was added to prepare PEG-graft-PACS copolymers by UV radiation. Then hydrazine monohydrate was employed to deprotect the phthaloyl group. FTIR and NMR were used to analyze the chemical structures of copolymers. DSC and TGA were employed to measure the thermal properties of the prepared copolymers. Swelling ratio was measured to understand the swelling behaviors at different pH values in order to evaluate potential applications of PEG-graft-CS copolymers .
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