| Summary: | 碩士 === 朝陽科技大學 === 生物技術研究所 === 97 === This research studied chitosan derivatives by chemically modifying the amine groups onchitosan molecules. Anhydrides of maleic acid, succinic acid and trimellitic acid were used to react with chitosan in methanol solvent system. The position of substitution was verified by IR spectra, and the degree of substitution was determined by quantif ying the degree of deacetylation. The effects of the types of amino substitution, the degree of substitution and molecular weight on the solubility in water and acetic acid solution were investigated. Experimental results showed a 3.75 times higher water s olubility for trimellitic acid derivatized chitosan (TMC) was obtained at a degree of substitution of 79.75%. Chitosan of various molecular weights were prepared by hydrolysis with 2% hydrogen peroxide for 12, 24, 48 and 72 hours at room temperature. The d egree of substitution was manipulated by controlling the reaction time. Improvements in solubility and the degree of substitution were more profound for reaction conditions of 0 -12 hours and 0-0.5 equivalent/-NH2, than of 12-24 hours and 0.5-1 equivalent/-NH2.
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