N-马来酰化壳聚糖的结晶形态  

Crystalline Morphologies of N-maleoyl Chitosan

作　　者：王惠武[1] 董炎明[1] 赵雅青[1] 毛微[1] 毕丹霞[1] 

机构地区：[1]厦门大学材料科学与工程系,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2004年第6期824-827,共4页Journal of Xiamen University：Natural Science

基　　金：国家自然科学基金(20374041);福建省自然科学基金(E0310002);福建省重点科技项目(2004I006)资助

摘　　要：采用间歇法合成了N 马来酰化壳聚糖,用FTIR和1H NMR测定其化学结构,并进一步用偏光显微镜、扫描电子显微镜研究其结晶形态.研究发现,在N 马来酰化壳聚糖的N,N 二甲基甲酰胺溶液浇铸膜中,先出现常见的树枝晶,然后观察到在树枝晶的末端生长出针状晶体和片状晶体两类不同的结晶形态,针状晶体最长为200μm,片状晶体的宽度平均约为20μm.对于针状晶体,分子链方向为轴向,而对于片状晶体分子链垂直于晶片的长轴方向.N-maleoyl chitosan was synthesized through two successive steps,and its chemical structure characterized by FTIR and confirmed by (~1H-NMR).Degree of substitution for maleoyl group in N-maleoyl chitosan is 0.79.Compared to chitosan,solubility of N-maleoyl chitosan in common organic solvent is of great enhancement.It can easily be soluble in dimethyl sulfoxide (DMSO),N,N-dimethyl formamide (DMF),N,N-dimethyl acetamide (DMAc) and formic acid (FA).Crystalline morphology of N-maleoyl chitosan is focused on in this paper.The polarized optical microscopy and scanning electron microscopy were used to study its crystalline morphologies.Dendritic crystals,needle-like crystals and lamellar crystals were found in N-maleoyl chitosan/DMF solution cast films.Dendritic crystals appeared in different time with different concentration.With increasing the concentration of N-maleoyl chitosan,the time which dendritic crystals appeared was longer.It attributed to the rigid segment of N-maleoyl chitosan.Two or three days after dendritic crystals appeared,it was also found that needle-like crystals and lamellar crystals grew on the ends of the dendritic crystals.The maximum length of needle-like crystals was about 200 μm, and the average width of lamellar crystals was around 20 μm.The director of molecular chain is different in the need-like crystals and lamellar crystals.In the former,the extended molecular chains were parallel to long axis;in the latter,however,the extended molecular chains were perpendicular to long axis.

关 键 词：晶体 酰化 枝晶 N-二甲基甲酰胺 结晶形态 壳聚糖 FTIR 片状 分子链 间歇法 

分 类 号：O636.1[理学—高分子化学] TQ325[理学—化学]