脱乙酰甲壳质和卡拉胶在溶液中的反应及其复合物性质研究

STUDY ON THE REACTION OF CHITOSAN WITH CARRAGEENAN IN SOLUTION AND THE CHARACTERISTICS OF THE COMPLEX

脱乙酰甲壳质(CTS)和卡拉胶(CGN)在溶液中反应生成不溶于水的沉淀,红外光谱分析及相反离子含量测定证明,CTS和CGN分子间的联结是以CTS分子中的-NH_3^+与CGN分子中的-SO_3^-通过静电相互作用来实现的。形成的聚电解质复合物N/S摩尔比在较宽的范围内依赖于反应混合溶液组成比、pH值及CTS的脱乙酰度。不同条件下形成的复合物具有不同的形态结构,当CTS分子与CGN分子上的电荷密度接近时,电镜观察到的复合物呈纤维状结构。复合物不溶于二甲基亚砜及CH_3COCH_3/KBr/H_2O(20∶20∶60wt)三元溶剂,在加热时溶于浓甲酸和稀盐酸,其溶解性随CTS脱乙酰度的增加而降低,CTS和CGN形成的聚电解质复合物具有一定的抗血凝性。

Solutions of chitosan and carrageenan were co-reacted under various experimental conditions to form water-insoluble hydrous precipitates. IR spectroscopic studies and the counter-ions analyses revealed that the combination of the polyions proceeded through the electrostatic interaction between the -NH_3^+ of chitosan and the -SO_3^- of carrageenan, and the mole ratios of N/S in the polyelectrolyte complexes (PEC) thus prepared have large scope depending on pH, the degree of deactylation (DD) of chitosan as well as the mixing ratio of the complexing components. The observation of the PEC by scanning electron microscopy showed that there exist fibrous structures in some PEC depending on such reactive conditions as pH, DD of chitosan elated -with the charge densities of chitosan chains. The solubility of PEC, which is greatly affected by the DD of chitosans, and the blood compatibility have also been studied.