甲壳素类液晶高分子的研究Ⅷ. N-邻苯二甲酰化壳聚糖/DMSO液晶溶液的热致相转变  

STUDIES ON CHITIN BASED LIQUID CRYSTALLINE POLYMERS Ⅷ. THERMOTROPIC PHASE TRANSITION OF N-PHTHALOLYL CHITOSAN/DMSO LIQUID CRYSTALLINE SOLUTIONS

作　　者：董炎明[1] 吴玉松[1] 阮永红[1] 赵雅青[1] 王惠武[1] 周花[1] 

机构地区：[1]厦门大学材料科学与工程系,厦门361005

出　　处：《高分子学报》2003年第5期714-717,共4页Acta Polymerica Sinica

基　　金：国家自然科学基金 (基金号 2 99740 2 3 )资助项目

摘　　要：合成了氮上完全取代的邻苯二甲酰化壳聚糖 (PhthCS) .用DSC研究了PhthCS DMSO液晶溶液的热致相转变 .偏光显微镜和DSC测定都表明临界浓度为 43wt% .在浓度高于 43wt%的溶液的DSC曲线中观察到了除了液晶 各向同性液体转变 (清亮点 )外还有一个明显的凝胶 溶胶转变 .凝胶 溶胶转变温度和转变焓均比文献报道的不规则取代的N 邻苯二甲酰化 O 乙酰化壳聚糖大得多 ,可见取代的规整性对凝胶 溶较转变有很大的影响 .根据DSC研究结果绘制了PhthCSN-phthalolyl chitosan with the degree of substitution 1 0 was prepared from completely deacetylated chitosan.Its chemical structure was characterized by means of FTIR and 1H-NMR.This polymer was used to investigate the thermotropic phase transition of lytropic liquid crystalline solutions in dimethylsulfoxide(DMSO) by using differential scanning calorimetry (DSC).The critical concentration of mesophase formation was 43 wt% determined both by DSC and polarizing light microscopy.An evident gel-sol transition in addition to a liquid crystal-isotropic liquid transition (the clearing transition) was observed by means of DSC in solutions whose concentration was higher than 43 wt%.It means that the isotropic liquid transferred into anisotropic sol and then into anisotropic gel with the decrease of temperature.The gel-sol transition temperatures and transition heats of N-phthalolyl chitosan/DMSO solutions were much higher than those of random substituted N-phthalolyl-O-acetyl chitosan solutions in some solvents reported previously.It may imply that the regularity of substitution is very important for the formation of anisotropic gel.A phase diagram of temperature and polymer weight fraction was presented according to the DSC results for the N-phthalolyl chitosan/DMSO system.

关 键 词：甲壳素 液晶高分子 N-邻苯二甲酰化壳聚糖 DMSO 热致相转变 溶致液晶 凝胶-溶胶 

分 类 号：O753.2[理学—晶体学]