【作者】 冯梦凰；

【导师】 董岸杰；

【作者基本信息】 天津大学 ， 材料学， 2004， 硕士

【摘要】 为了改善壳聚糖的溶解性,本文对聚乙二醇单甲醚(MePEG)接枝改性壳聚糖进行了研究。首先,通过官能团偶联反应,将端基改性为醛基的聚乙二醇单甲醚接枝到壳聚糖分子链上,制得了梳状、可溶于水的聚乙二醇单甲醚接枝壳聚糖(CTS-g-MePEG)。采用元素分析、红外光谱和透射电镜等方法对产物的结构和性质进行了表征。研究表明,所制得的CTS-g-MePEG在水溶液中能够自组装成胶束,且在酸性溶液中表现出有别于壳聚糖的流变性。采用上述方法,本文还制备了可以在更广泛的pH值范围内分散的聚乙二醇单甲醚接枝羧甲基壳聚糖(CMCTS-g-MePEG),并对其流变性、两性聚电解质性质及其与水溶性壳聚糖的复合行为进行了研究。为了保留壳聚糖上的氨基,本论文探索了另一种接枝改性壳聚糖的途径,即用邻苯二甲酸酐对壳聚糖上的氨基进行保护,然后用甲苯二异氰酸酯为偶联剂将聚乙二醇单甲醚接枝到壳聚糖大分子链上,最后用水合联氨为还原剂解除对氨基的保护。实验结果表明,该方法可以使氨基得到保护,并能把聚乙二醇单甲醚接枝到壳聚糖上,但水合联氨在脱保护氨基的同时也还原了接枝链上的氨酯键,导致了聚乙二醇单甲醚的去接枝化。更多还原

【Abstract】 In order to improve the poor solubility of chitosan, monomethoxy poly(ethylene glycol) grafted chitosan(CTS-g-MePEG) were prepared by the reacting of aldehyded monomethoxy poly(ethylene glycol) and the 2-amino functions of chitosan. The obtained comb-shaped CTS-g-MePEG products present good watersolubility. Elemental analysis、IR spectroscopy and TEM methods were used to estimate the properties of the grafted products. The results indicate that the prepared CTS-g-MePEG can self-assemble into micelles in distilled water solution. Moreover, the grafted chitosan presents different rheological property from chitosan in acidic medium. Using the same method, the present paper also prepared monomethoxy poly(ethylene glycol) grafted carboxymethyl chitosan(CMCTS-g-MePEG), which can be dispersed in water over all pH range. The rheological property, amphoteric polyelectrolyte property and the complexing behavior of CMCTS and CMCTS-g-MePEG with water-soluble chitosan were investigated. In order to remain the free amino groups on chitosan, chitosan-O-monomethoxy poly(ethylene glycol) was prepared by the grafting of MePEG-NCO to the hydroxyl groups of N-phthaloyl chitosan. The phthaloyl groups were removed with hydrazine monohydrate to regenerate the free amino groups. The results showed that the amino groups can be protected by phthalic anhydride and MePEG can be grafted onto CTS at the hydroxyl groups. But unfortunately, the hydroxyl groups were partly deoxidised during the process of deoxidizing phthaloyl groups by hydrazine monohydrate.更多还原