Studies on the synthesis and properties of chitosan/acrylic acid copolymer
| Autor: | C. Y. Chuang, 莊仲揚 |
|---|---|
| Rok vydání: | 2001 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 89 The copolymerizations of chitosan/acrylic acid(CS/AA) were studied in this research. The physical properties of CS/AA copolymers were discussed in this work. Two different initiators, namely, potassium persulfate(KPS) and cerium ammonium nitrate(CAN),were used to initiate the copolymerization of acrylic acid onto chitosan chains. With KPS initiator, a block copolymer of CS/AA was produced during the polymerization and the polyelectrolyte complex precipitated out from the solution was observed. Yet, a grafted copolymer was obtained if using the CAN initiator, and the final product was in a gel form. The CS/AA copolymer, not only raised the glass transition temperature (Tg) of PAA, but also improved the ability of anti-acidic of chitosan. If the CS/AA solution were casted into dried film, the dense membranes were found. But, in different pH value or in different ionic solution, the morphologies of wetted membranes changed because of the polyelectrolyte complex structure in copolymers. The swelling behaviors of the copolymers were affected by surrounding pH value、ionic strength and the types of ion. The CS/AA copolymers had swelling ratio maximum at pH=7 or in high charge ionic solution. The chelating behavior of the copolymers showed the difference capabilities in chelating copper ion and chelating iron ion. As the content of chitosan raised in copolymer, the amount of copper adsorption increased, but the amount of iron adsorption decreased. The CS/AA copolymers were degraded in enzyme solution and active slurry solution. But, the fibroblast cell could not survive on the copolymers because of the polyelectrolyte complex structure and the high hydrophilic affinity. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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