本研究是將幾丁聚醣溶於甲酸溶劑中，再加到N,N-二甲基甲醯胺與鄰苯二甲酸酐的溶液系統中，進行均相的化學反應修飾，利用鄰苯二甲酸酐與幾丁聚醣的胺基反應，藉此保護胺基及改善其有機溶劑溶解性。分別利用元素分析與紫外線可見光光譜分析求出鄰苯二甲酸酐之取代度，在相同反應的條件下，兩種不同方法求出來的結果彼此吻合。利用紅外線光譜及固態核磁共振光譜針對產物作結構分析，結果顯示在高溫反應下，幾丁聚醣確實與鄰苯二甲酸酐有化學反應，且隨著反應時間的增加而有取代度增加的趨勢。反應後之產物可溶於如N,N-二甲基甲醯胺、N,N-二甲基乙醯胺和二甲亞碸有機溶劑。再利用幾丁聚醣上的氫氧基與二環氧基醚聚乙二醇進行接枝反應，並加入陽離子型光起始劑，以UV光交聯得到幾丁聚醣二環氧基醚聚乙二醇接枝的產物，利用元素分析求出取代度。之後再利用聯胺去保護還原幾丁聚醣的胺基，並針對產物作結構分析、熱分析以及澎潤比等測試，藉以評估聚乙二醇接枝幾丁聚醣材料的性質和其它方面的應用性。 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 .
