聚吡咯衍生物的合成及液晶性能

系统论述了新型导电功能性液晶聚合物3-和N-液晶基元取代聚吡咯的合成和液晶行为。指出通过化学氧化聚合、电化学氧化聚合和脱卤缩合聚合可以获得液晶性聚吡咯衍生物。它们均显示热致液晶行为，且多数呈现近晶液晶相，少数呈现向列液晶相，有些具有2种近晶相，有些具有单变液晶性。N-液晶基元取代聚吡咯比3-位取代聚吡咯具有较高的液晶稳定性。较长的亚甲基间隔和极性的介晶基团能够使N-取代聚吡咯具有较大的液晶微区和稳定的液晶相。N-取代液晶聚吡咯在摩擦力的作用下还可以诱发单轴取向。这种热致液晶性聚吡咯衍生物的研究成功有希望克服聚吡咯难以成型加工的巨大障碍。     

Scaling properties of ℤ k- 1 actions on the circle

We derive universal scaling properties for ^k–1 actions on the circle whose generators have rotation numbers algebraic of degreek. As fork=2 these properties can be explained for arbitraryk in terms of a renormalization group transformation. It has at least one trivial fixed point corresponding to an action whose generators are pure rotations. The spectrum of the linearized transformation in this fixed point is analyzed completely. The fixed point is hyperbolic with a (k–1)-dimensional unstable manifold. In the casek=2 the known results are therefore recovered.     

A facile synthesis of aliphatic polybenzoxazoles from a bis(o-aminophenol) or its hydrochloride and aliphatic dinitriles

A facile one-step method for the synthesis of aliphatic polybenzoxazoles has been developed. Thus, a series of aliphatic polybenzoxazoles having inherent viscosities of 0.2–0.7 dL/g in concentrated sulfuric acid were successfully synthesized by the melt polycondensation of alipatic dinitriles with 4,4′-diamino-3,3′-dihydroxybiphenyl (AHB) or its hydrochloride (AHB–HCl) with the elimination of ammonia or ammonium chloride, respectively. Monomer AHB–HCl was more reactive than the parent AHB, thereby affording higher molecular weight polybenzoxazoles in a shorter reaction time. The aliphatic polybenzoxazoles having 6–10 methylene units were highly crystalline with melting temperatures in the range of 187–308°C, which were stable up to 400°C in a melt state in nitrogen. © 1994 John Wiley & Sons, Inc.     

羟基化合物及其葡醛酸苷化学结构与RP—HPLC保留行为相关性研究

采用体外孵育生物合成方法获得羟基化合物葡醛酸苷系列化合物，并对其反相高效液相色谱保留行为及底物与其葡醛酸结合物保留行为相关性进行了研究，建立了相应的结构－色谱保留行为相关性方程及葡醛酸苷类代谢物保留行为的预测方法。将ＱＳＲＲ研究扩展到药物代谢物领域，对药物Ⅱ相葡醛酸化代谢产物的ＨＰＬＣ分析提供了帮助。     

稀土-二甲酚橙络合物的胶束液相色谱分离与测定

本文应用一种新的高效液相色谱-胶束液相色谱法,在Shim-Pack CLC-ODS(150mm×6.0mm)色谱柱上,用含1.6×10~(-2)mol/L的CTMAB和pH=7.40的三-(羟甲基)-氨基甲烷缓冲液的甲醇/水(5:95)作流动相,对15种稀土元素-二甲盼橙络合物进行分离,取得了较满意的结果。     

丙烯酸酯接枝炭黑无皂水性涂料的性能研究

旋转粘度计研究了丙烯酸酯接枝炭黑无皂水性涂料的流变性能，并考察了着色涂料的冻融及贮存稳定性。接枝炭黑争散于无皂水性涂料中形成的着色涂料具有良好的综合性能。     

Investigation on property and mechanism of redox wave of methylhesperidine at Hg electrode

The voltammetric behaviors of methylhesperidine (MH) were studied by means of linear sweep voltammetry, cyclic voltammetry and normal pulse voltammetry. In the Brit-ton-Robinson buffer solutions with pH values from 2.05 to 6.37, MH could yield three reduction waves PC1,PC2 and PC3. PC1 wave is an adsorptive pre-wave. PC2 wave is an irreversible reduction of pre-protonated MH involving one electron and one proton. PC3 wave is an irreversible wave of reduction species radical of MH involving one electron.     

有机小分子染料和聚阳离子分子超薄膜的制备及其摩擦学性能研究

制备了以有机小分子染料酸性红 1 8为阴离子、以聚烯丙基氯化铵和聚乙烯亚胺为聚阳离子的分子沉积膜 ,用紫外可见分光光度计、接触角测定仪和椭圆偏振光测厚仪对所制备的超薄膜进行了表征 .用DF PM型动 静摩擦系数精密测定装置考察了超薄膜的摩擦学性能 ,采用扫描电子显微镜对薄膜的磨痕表面进行了观察 .结果表明 ,所制备的超薄复合沉积膜具有良好的减摩和耐磨性能     

Metal complexes of a homopolymer system containing diethanolamine side group: synthesis and dielectrical behaviors

In this work, 4-diethanolaminomethyl styrene (DEAMSt) monomer was prepared by modification of 4-chloromethyl styrene with diethanolamine. The homopolymerization of styrene modificated was carried out by free radical polymerization method at 60?°C in presence of 1,4-dioxane and AIBN. The metal complexes were prepared by reaction of the homopolymer used as ligand P(DEAMSt)L^l and Ni(II), Co(II) metal ions in presence of ethanol and dilute NaOH at 65?°C for 48?h in pH 6.

The structure of modificated monomer, homopolymer used as ligand and polymer-metal complexes were characterized by (FT-IR), ¹H-NMR, ¹³C-NMR, Raman spectroscopy tecniques, elemental analysis, SEM, XRD and magnetic measurements. Their geometric structures according to magnetic measurements of Co(II) and Ni(II) complexes were estimated that have a tetrahedral structure. P(DEAMSt)L^l polymer has a transition state between amorphous and crystalline, whereas metal complexes (Co(II) and Ni(II) are with a large crystal structure. The molecular weight of P(DEAMSt)L¹ homopolymer was determined by gel permeation chromatography (GPC). The glass transition temperature (Tg) of homopolymer was measured by differantial scanning calorimeter (DSC). The thermal behaviors of both ligand and polymer-metal complexes were investigated by thermogravimetric analysis (TGA) and (DTA). The results obtained were compared with each other. Then, the dielectrical measurements (dielectric constant, dielectric loss and conductivity) of the ligand and polymer-metal complexes were investigated as a function of temperature and frequency. The activation energies (Ea) of the ligand and metal complexes were determined from the conductivity measurements.     

Fluorescence Probe Studies of Ionic Micelles in Concentrated Salt Solutions

We have investigated the effect of salt concentration and temperature on the average aggregation number and micro-polarity of the interior of micelles of sodium dodecyl sulfate (SDS). sodium tetradecyl sulfate (STDS) and lithium dodecyl sulfate (LiDS). The transient fluorescence decay of micelle-solubilized pyrene has been measured and analyzed. An exponent weighted average aggregation number <n>_e was obtained by this technique. For SDS and STDS in NaCl solution, <n>_e increases as the temperature is lowered or salt concentration is increased <n>_e increased from ～ 50 to ～ 250 over [NaCl] = 0 to 0.8 M. Due to the strong counterion binding of lithium in the micellar solution, the LiDS micelle is much, smaller and does not increase appreciabily even at [LiCl] =0.8 M. From the fluorescence spectrum fine structure of pyrene and the fluorescence decay of the monomer and excimer, we can understand the local polarity and the water penetration to the interior of the micelle upon addition of salts and with changing temperature. The interior of the micelle becomes more nonpolar as the salt concentration is increased and the temperature is lowered. A complete kinetic analysis of the time–dependence of the fluorescence is given. The kinetic analysis is in agreement with the results reached by fluorescence spectral analysis.