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STUDIES OF DILUTE AND CONCENTRATED SOLUTION PROPERTIES OF NATURAL POLYSACCHARIDES

天然多糖稀、浓溶液性质研究

基本信息

批准号：
61470102
负责人：
TERAMOTO AKIO
金额：
$ 4.03万
依托单位：
OSAKA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

DILUTE AND CONCENTRATED SOLUTIONS OF POLYSACCHARIDES, SCHIZOPHYLLAN (TRIPLE-STRANDED, NONIONIC) AND XANTHAN (DOUBLE-STRANDED, IONIC), WERE STUDIED BY LIGHT SCATTERING, POLARIMETRY, TITRATION, CALORIMETRY, AND VISCOMETRY, THE MAIN RESULTS AND CONCLUSIONS ARE AS FOLLOWS.1. SCHIZOPHYLLAN IN AQUEOUS SOLUTION UNDERGOES A COOPERATIVE TRANSITION BETWEEN THE ORDERED AND DISORDERED STATES IN THE SIDE CHAIN CONFORMATION, EXHIBITING A PRONOUNCED ISOTOPE EFFECT.2. THE DOUBLE HELIX OF XANTHAN (NA SALT) IN 0.01 M AQUEOUS NAC1 MELTS INTO A DIMERIZED COIL.3. TERNARY SOLUTIONS CONSISTING OF WATER AND TWO SCHIZOPHYLLAN SAMPLES DIFFERENT LARGELY IN MOLECULAR WEIGHT WERE FOUND TO SEPARATE INTO THREE PHASES, TWO CHOLESTERIC PHASES AND ONE ISOTROPIC PHASE.4. AQUEOUS NAC1 SOLUTIONS OF XANTHAN ALSO FORM CHOLESTERIC LIQUID CRYSTALS.5. THE THEORIES FOR ISOTROPIC-LIQUID CRYSTAL PHASE EQUILIBRIUM IN BINARY SEMIFLEXIBLE POLYMER SOLUTIONS ARE COMPARED FAVORABLY WITH DATA FOR VARIOUS POLYMERS INCLUDING SCHIZOPHYLLAN AND XANTHAN.6. THE PHOTON CORRELATION SPECTROMETER CONSTRUCTED IN THIS WORK GAVE ACCURATE DIFFUSION COEFFICIENTS FOR POLYSTYRENE AND ITS LATEX. THE MEASUREMENT ON XANTHAN SOLUTIONS IS NOW IN PROGRESS.7. A MAGNETIC RHEOMETER WAS CONSTRUCTED AND USED TO MEASURE VISCOSITIES OF ISOTROPIC XANTHAN SOLUTIONS AS A FUNCTION OF NAC1 AND POLYMER CONCENTRATIONS. THEY WERE FOUND TO BE ALMOST INDEPENDENT OF NAC1 CONCENTRATION, REFLECTING THE INTRINSICALLY HIGH RIGIDITY OF THE XANTHAN DOUBLE HELIX.

采用光散射法、极化法、滴定法、量热法和粘度法对三链非离子型裂叶多糖和双链离子型黄原胶的稀、浓溶液进行了研究，主要结果和结论如下：分叶植物在水溶液中侧链构象的有序态和无序态之间发生协同转变，表现出明显的同位素效应。黄原胶（钠盐）的双螺旋结构在0.01 m水溶液中溶解成二聚体。由水和两种分子量相差很大的裂叶植物样品组成的三元溶液可分离成三个相，两个甾相和一个各向同性相。黄原胶水溶液也可形成胆甾型液晶。将二元半柔性聚合物溶液中各向同性-液晶相平衡的理论与包括裂叶藻和黄原胶在内的各种聚合物的数据进行了比较。本文所建立的光子相关谱仪能准确测定聚苯乙烯及其胶乳的扩散系数。对黄原胶溶液的测定正在进行中。建立了磁性流变仪，用于测量各向同性黄原胶溶液粘度随nac1和聚合物浓度的变化。它们几乎不受nac1浓度的影响，反映了黄原胶双螺旋结构固有的高刚性。