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几丁聚糖是由几丁质脱乙酰而来的一种线性高分子多糖 ,其 β- 1,4糖苷键在酸性条件下不稳定 ,易发生长链的水解。本文通过醋酸降解法制备了不同相对分子质量的几丁聚糖 ,经测定降解前后产物的脱乙酰度未发生改变。将降解的几丁聚糖配制成 3%的醋酸溶液 ,50℃烘干后用碱中和制成几丁聚糖膜 ,膜透明 ,吸水后有弹性 ,强度好。将膜固定在自制的通透装置中研究比较了不同相对分子质量几丁聚糖膜对氯化钠、L-Tyr、葡萄糖以及牛血清白蛋白的通透性 ,结果表明膜对 4种物质均有通透性 ,且通透性与相对分子质量相关 ,分子量越小 ,对 4种物质的通透性越好
Chitosan is a linear polymeric polysaccharide derived from the deacetylation of chitin. Its β-1,4 glycosidic bond is unstable under acidic conditions and prone to long-chain hydrolysis. In this paper, chitosan with different molecular weights was prepared by acetic acid degradation method. The degree of deacetylation of the product before and after degradation was not changed. The degraded chitosan was formulated into a 3% acetic acid solution, dried at 50°C and neutralized with alkali to make a chitosan membrane. The membrane was transparent, elastic after being absorbed, and had good strength. The membrane was fixed in a self-made permeation device and the permeability of chitosan membranes of different relative molecular mass to sodium chloride, L-Tyr, glucose, and bovine serum albumin was compared. The results showed that the membrane was suitable for all four substances. Permeability, and permeability is related to the relative molecular mass, the smaller the molecular weight, the better the permeability to the 4 substances