| Summary: | 博士 === 大同大學 === 化學工程學系(所) === 96 === A novel bio-affinitive, photocuring and membrane-forming gelatin derivative was synthesized in this study. This process was based on the amide formation between carboxylic acid and the amine in methanol-water media using dicyclohexyl- carbodiimide (DCC) as a condenser. Gelatin and glycine were the sources of amine in the model reaction. Since there were two anhydride groups in each 3,3',4,4'-benzophenone tetra-carboxylic di-anhydride (BTDA) molecule, two 2-hydroxyethyl methacrylate (HEMA) molecules were used to induce the ring-opening reaction of BTDA and release two carboxylic acid groups. The resulting photoreactive gelatin was called GE-BTHE, of which the photoreactive component was the ketone groups of BTDA and HEMA that played the role of double bond supplier. This photoreactive gelatin could be converted from the transparent liquid phase into swollen membrane by a 6-minute irradiation of high pressure mercury lamp. The most efficient irradiation was at 267 nm and the highest degree of swelling of the cured GE-BTHE membrane could reach 5.9. The elongation from the dried gel remained 5-10%, i.e. relatively elastic. The properties of this gelatin derivative were investigated using amide formation analysis, calculation of the gel content and the swelling ratio, and monitoring of the photocuring process. The membranes of GE-BTHE were also examined with atomic force microscopy (AFM), scanning electron microscopy (SEM) and UV-vis spectroscopy. The results revealed that UV irradiation could bring about both photo-crosslinking as well as photo-degradation in the GE-BTHE membrane. The maximum absorbance of UV irradiation occurred in the range of 267 to 275 nm. Once the membrane was further irradiated at 254 nm, phase transformation took place. The GE-BTHE synthesized in this study should be very potential in biomedical and industrial applications. Furthermore, the photo-crosslinking and photo- degradation behavior of GE-BTHE also makes it more useful such as protective wound dressings and hemostatic absorbents for minimally invasive surgery.
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