甲壳素类液晶高分子的研究Ⅳ.脱乙酰度对壳聚糖液晶性的影响  

STUDIES ON CHITIN-BASED LIQUID CRYSTALLINE POLYMERS Ⅳ. EFFECT OF DEGREE OF DEACETYLATION ON THE LIQUID CRYSTALLINE BEHAVIORS OF CHITOSAN

作　　者：汪剑炜[1] 董炎明[1] 李旭升 

机构地区：[1]厦门大学化学化工学院材料科学系和固体表面物理化学国家重点实验室,厦门361005

出　　处：《高分子学报》2000年第6期732-735,共4页Acta Polymerica Sinica

基　　金：国家自然科学基金!(基金号 2 99740 2 3);福建省自然科学基金!(基金号z9910 0 0 6 )

摘　　要：通过壳聚糖乙酰化法制备了不同脱乙酰度的壳聚糖 ,并研究了脱乙酰度这一结构因素对壳聚糖溶致液晶性的影响 .观察到脱乙酰度为 5 0 %左右时 ,壳聚糖在水中和二氯乙酸中的溶致液晶临界浓度最高 .壳聚糖在水中的溶致液晶临界浓度远低于在二氯乙酸中的临界浓度 .The effects of molecular weight,degree of substitution and side chain length on the liquid crystalline behaviors of chitin derivatives have been studied.It is known that the molecular weight affects the liquid crystalline behaviors evidently.To study the effect of degree of deacetylation (D.D.),the samples with different D.D. but with same molecular weight must be prepared.These samples were prepared by acetylating chitosan with different amount of acetic anhydride and different reaction time.The method took the advantage of less degradation of molecular chains and no acetylation on —OH of C3 and C6.The chitosans with different D.D.all exhibited typical liquid crystalline texture.The chitosan sample with about 50% D.D. was found to be water soluble and have the maximum critical concentration of lyotropic liquid crystal in both dichloroacetic acid and water.The critical concentration values in water were much lower than those with the same degree of deacetylation in dichloroacetic acid.The poorer liquid crystallinity of chitosan with about 50% D.D.can be explained by the random distribution of acetylamino\| D glucose units and amino\| D glucose units.

关 键 词：壳聚糖 脱乙酰度 溶致液晶 临界浓度 水溶性 

分 类 号：O636.1[理学—高分子化学] O631.1[理学—化学]