本研究主要是以幾丁聚醣(CS)為材料，先利用鄰苯二甲酸酐和幾丁聚醣的胺基反應，藉以保護具有生物活性的胺基以及增加幾丁聚醣在有機溶劑中的溶解性；接著利用3-異丙烯基-α,α-二甲基卞基異氰酸鹽（TMI）與經鄰苯二甲酸酐修飾後的幾丁聚醣上的-OH基反應，使幾丁聚醣擁有雙鍵。再利用聯胺水溶液反應以去除鄰苯二甲酸酐保護基而得到我們所需的產物（CS-TMI），再將此產物加入不同比例的氮-異丙基丙烯醯胺單體，利用光聚合反應聚合形成幾丁聚醣接枝聚氮-異丙基丙烯醯胺共聚物。利用FTIR、NMR可以知道利用苯酸酐保護了大量的胺基、並且成功的接上TMI於幾丁聚醣醣環的-OH上，並留有雙鍵，利用元素分析可以知道 TMI 的取代度為0.25。利用重量法計算幾丁聚醣接枝聚氮-異丙基丙烯醯胺共聚物的單體轉化率、接枝效率及接枝比值，結果發現單體轉化率和接枝比值隨著單體添加量的增加而增加，最大的接枝比值可以到達3.42，而接枝效率則都維持在90％左右。所合成出來的共聚物同時擁有溫度敏感性以及酸鹼敏感性。將此共聚物進行結構分析、熱分析、膨潤比、LCST、細胞培養等測試。測試結果顯示此共聚物為接枝型共聚物，由於擁有幾丁聚醣鏈段，在酸性環境下膨潤性最大，而溫度敏感性則隨著PNIPAAm接枝量的增加而越明顯，共聚物的LCST值則和純的PNIPAAm一樣維持在32oC，並且無細胞的毒性。 In this research, phthalic anhydride(PA) was ued to react with the amino group of chitosan to protect amino group and increase chitosan solubility in organic solvent. Then 3-Isopropenyl-α,α-dimethylbenzyl isocyanate(TMI) was reacted with the hydroxyl group of PA substituted chitosan, that introduced double bond to chitosan. Subsequently hydrazine hydrate was used to remove PA and bing amino group back to CS(CS-TMI). Finnally different amounts of N-isopropylacrylamide monomer(NIPAAm) and photoinitiator were added to prepare PNIPAAm-graft-chitosan copolymers by UV irradiation. FTIR and NMR were used to characterize and confim the structures of PA-substitated CS and TMI-CS. From the elemental analysis, we could decide the degrees of substitution of PA as well as TMI in chitosan. The degree of TMI substitution was calculated to be 0.25. Afte UV-initiated graft polymerization of NIPAAm onto TMI-CS. We found that the conversion and grafting ratio were both inceased with increasing monomer amount. The maximum grafting ratio obtained was 3.42 and the grafting efficiency maintained at about 90％. The synthesized copolymer had dual thermal and pH-sensitive properties. DSC and TGA were employed to measure the thermal properties of the prepared copolymers. Swelling ratio was measured to understand the pH and thermal responsive behaviors. Finally, cell biocompatibility was evaluated by cell culture and MTT test on the membranes.
