- 學位論文
具有酸鹼及溫度敏感性之幾丁聚醣水凝 膠合成及性質之研究
Synthesis and Properties of the Thermal and pH Sensitive Chitosan Hydrogel
摘要
本研究以Diels Alder 反應以及Michael addition 反應為主軸進行 幾丁聚醣和聚乙烯醇的交聯反應，以製備水凝膠與膜材。交聯反應分 為三個系統：(1) 以furan 官能基改質幾丁聚醣，再利用其具有的furan 官能基與三官能馬來醯胺化合物TMI 進行Diels Alder 反應產生交 聯，同時幾丁聚醣上的胺基會與TMI 上的馬來醯胺基發生Michael Addition 反應進行交聯而形成水凝膠。將此水凝膠進行不同溫度與不 同pH 值環境下之膨潤度測試，發現此水凝膠在pH=1 與pH=7 緩衝 溶液之間，具有可逆膨潤之性質，於是利用此特性進行藥物釋放實 驗，結果顯示此水凝膠於pH=1 時環境下之藥物釋放量大於pH=7 之 環境，所以可以做胃部治療藥物的載體。(2)利用同時帶有羧基與馬 來醯胺基之單體，與幾丁聚醣之胺基分別進行醯胺化反應及Michael Addition 反應進行而產生交聯，並將其製備成膜材。由於交聯反應， 故膜材機械性質提昇，並由於單體(p-CPM, CPM)帶有羧基，所以膜 材具有親水之特性，故可應用於滲透蒸發。(3)設計帶有furan 官能基 的聚乙烯醇衍生物，即可利用其furan(diene)與兩端帶有馬來醯胺官 能基之BMI 進行Diels- Alder 反應，形成水凝膠。之後將此水凝膠製 備成膜，對其進行機械性質及熱性質等分析，發現其機械性質與熱性 質均較純聚乙烯醇膜材有所提升。
關鍵字
幾丁聚醣並列摘要
The aims of this work is to prepare chitosan and poly(vinyl alcohol) (PVA) hydrogels through Diels Alder and Michael addition reactions. The first hydrogels are obtained from crosslinking a furan-containing chitosan with a tri-maleimide compound. The crosslinking reactions were performed through both of the Diels-Alder reaction and Michael addition reaction. The swelling behavior of those hydrogels in deionized water at different temperatures and different pH buffer solutions were investigated. The hydrogels have reversible swelling behavior between pH=1 and pH=7 buffer solutions. Taking advantage of this reversible swelling behavior, the hydrogels were used as a controlled drug release material. Due to the swelling ratio in pH=1 is larger than in pH=7, the drug release in pH=1 solution is higher than that in pH=7 one. The second part includes preparation of membranes from dehydration and Michael addition reactions between the carboxyl and maleimide groups of monomer and amine group of chitosan. Mechanical properties of crosslinked membranes are better than that of the pristine chitosan membrane. Because the monomer (p-CPM, CPM) has carboxyl group, the membranes are highly hydrophilic and potentially applicable for Pervaporation dehydration. The third part represents the membranes prepared from hydrogels, which was obtained from Diels Alder reaction between furan group of a modified PVA and the maleimide group of bismaleimide. The prepared membrane exhibited enhancements on thermal and mechanical properties comparing to the unmodified PVA membrane.