N,O-羧甲基壳聚糖的合成和性质研究  

Synthesis and Studies on Properties of N,O-Carboxymethylchitosan

作　　者：吴刚[1] 沈玉华[1] 谢安建[1] 林宏云[1] 郭文豪[1] 

机构地区：[1]安徽大学化学化工学院,合肥230039

出　　处：《Chinese Journal of Chemical Physics》2003年第6期499-503,共5页化学物理学报（英文）

基　　金：heProjectSupportedbyNNSFC (2 0 0 310 10;2 99710 0 1);KPME0 0 180andNSFAHP (0 0 4 5 115 )

摘　　要：采用多段升温法将壳聚糖改性 ,合成了取代度为 1.84、平均分子量为 3.0 8× 10 5、等电点为 7.2 8的N ,O 羧甲基壳聚糖 (CMC) ,分别用紫外光谱、红外光谱、荧光光谱对其结构进行了表征 ,并对其水溶液的Zeta电位、电导率、表面张力以及水分散体系中羧甲基壳聚糖微粒的粒径分布进行了研究 .结果表明 ,N ,O 羧甲基壳聚糖具有表面活性 ;N,O-Carboxymethylchitosan(CMC) beginning with chitosan and chloracetic acid by stepwisely increasing temperature method was synthesized. Carboxymethylation substitutive degree is 1.84, average molecular weight is 3.08x10(5) and instrinsic viscosity (25+/-0.5)degreesC is 180 L/g. It was characterized by ultraviolet spectrum, infrared spectrum, fluorescence spectrum. Its ultraviolet characteristic absorption peak is at 206 nm arising from n-->pi electron transition. However, the ultraviolet characteristic absorption peak of chitosan is at 195 nm. One of stretching vibration absorption peak of CMC infrared spectrum is at 1635 cm(-1) which results from stretching vibration of -C=O(-COOH) bond. But at 1635 cm(-1) there is no stretching vibration peak of C=O in the chitosan infrared spectrum. In fluorescence spectrum, the excitation wavelength of CMC is 330 nm and its emission wavelength is 407 nm. The excitation wavelength of Chitosan is 320 nm and its emission wavelength is 391 nm. Synthesized CMC is soluable in the aqueous solution. It is a macromolecular surface-active agent. CMC surface tension linearly decreases with the increasing of CMC concentration in aqueous solution. But its conductivity linearly increases with the increasing of CMC concentration in the aqueous solution. The CMC aggregate behaviors in CMC aqueous solution is also studied, which shows that there is a some degree aggregation in the aqueous solution of synthesized carboxymethylchitosan. Meanwhile, the Zeta potential of CMC aqueous solution is studied. It demonstrates that Zeta potential value decreases with the decreasing of the concentration of CMC: The study indicates CMC is an amphoteric macromecleular electrolyte and its isoelectronic point is 7.28. Therefore, the pH value and concentration of CMC have great influence on the stability of CMC aqueous solution.

关 键 词：N O-羧甲基壳聚糖 CMC 聚集 表面张力 电导率 ZETA电位 合成 性质 表面活性 

分 类 号：O636.1[理学—高分子化学]