芴酮对聚醚侧链聚芴体系的影响: 合成, 表征及光物理性质的研究

利用Yamamoto聚合反应, 通过调节单体2,7-二溴9,9'-二-(三乙氧基甲基)芴和2,7-二溴芴酮的比例, 合成了侧链为极性聚醚链, 芴酮含量逐渐增加的聚芴系列. 通过聚合物溶液及固态薄膜的紫外荧光谱图, 深入研究芴酮作为能量受体的能量转移过程及其对聚合物光物理性质的影响. 结果表明: 稀溶液中体系呈现聚芴本征态的荧光发射, 能量转移对溶液浓度具有依赖性; 固态薄膜中能量转移效率随芴酮含量的增加而快速增长, 退火后这种现象更加明显.     

双酚芴双胺型苯并嗯嗪树脂的合成、结构及热性能

以9-芴酮、苯酚为原料,以质量分数为98%的浓硫酸为催化剂,2-巯基丙酸为助催化剂,合成了双酚芴[9,9-双(4-羟苯基)芴],再用其与乙二胺和多聚甲醛反应,合成了线性双酚芴双胺型苯并噁嗪树脂(BF-eda树脂).采用FTIR,'H NME和<'13>C NMR等分析手段对双酚芴和BF-eda树脂的化学结构进行了表征;...     

螺[二苯并[a,j]氧杂蒽-14,9'-芴]的合成及性质

芴酮与2-萘酚在硫酸和3-巯基丙酸的作用下反应得到化合物螺[二苯并[a,j]氧杂蒽-14,9'-芴]. 采用核磁共振、 质谱、 红外光谱和元素分析等对该化合物进行了表征, 并通过X射线衍射法测得了其晶体结构, 确定该化合物是通过二苯并[a,j]氧杂蒽中的含氧六元杂环和芴中的五元环共用一个碳原子形成一个螺环. 利用荧光光谱和热分析等手段对该化合物的性质进行了研究, 结果表明其最大荧光发射峰为366 nm, 熔点为297 ℃, 热分解温度为329 ℃, 具有较高的热稳定性.     

螺[二苯并[a,j]氧杂蒽-14,9’-芴]的合成及性质简

芴酮与2-萘酚在硫酸和3-巯基丙酸的作用下反应得到化合物螺[二苯并[a,j]氧杂蒽-14,9’-芴]. 采用核磁共振、质谱、红外光谱和元素分析等对该化合物进行了表征,并通过X射线衍射法测得了其晶体结构,确定该化合物是通过二苯并[a,j]氧杂蒽中的含氧六元杂环和芴中的五元环共用一个碳原子形成一个螺环. 利用荧光光谱和热分析等手段对该化合物的性质进行了研究,结果表明其最大荧光发射峰为366 nm,熔点为297 ℃,热分解温度为329 ℃,具有较高的热稳定性.     

可光固化单体2,7-二溴-9,9-双[4’-(3″-乙基-3″-氧杂环丁烷甲氧基己基氧基)苯基]芴的合成

以芴为原料,经溴代和氧化反应制得2,7-二溴芴酮(3);3与苯酚反应合成2,7-二溴-9,9-双(4’-羟基苯基)芴(4);4与3-(6’-溴己氧基甲基)-3-乙基氧杂环丁烷经醚化反应合成了可光固化单体2,7-二溴-9,9-双[4’-(3″-乙基-3″-氧杂环丁烷甲氧基己基氧基)苯基]芴,总收率67%,其结构经1H NMR,13C NMR和元素分析表征。     

9,9-二(3-苯基-4-羟基苯基)芴的合成

9,9-二(3-苯基-4-羟基苯基)芴是以芴酮和联苯酚为原料在酸性催化剂存在下经缩合反应而制得的Cardo骨架结构的双酚类化合物。考察了物料配比、反应温度和时间对反应收率的影响,并经过正交实验,确定了反应的最佳工艺条件:反应温度120℃,反应时间为12 h,n(芴酮)∶n(联苯酚)=1∶10,产品收率为85%,纯度99.5%(HPLC面积归一化法)。产品结构经~1H-NMR表征。     

聚芴类半导体光谱稳定性

有机半导体的物理和化学性质直接影响其光电器件的性能, 这为物理化学提出了新的研究内容与挑战. 其中, 聚芴类蓝光二极管的光谱稳定性及低能发射带(LEEB)的起源问题是国际上近十年的热点问题之一. 本文系统概述了低能发射带的现象、表征方法以及可能的形成机理, 包括链间作用导致的激基缔合物发射、器件制备或降解过程形成的芴酮缺陷发射、芴酮聚集态发射以及聚芴端羟基界面氧化导致的绿光发射. 本文综述各种物理掺杂和界面调控改善聚芴类二极管蓝光稳定性的策略, 着重论述非平面基团的空间位阻、分子构象与链的拓扑结构以及引入抗氧化受阻胺光稳定剂来提高其光谱稳定性策略.     

芳基喹啉取代螺二芴化合物的合成

2-溴联苯格式试剂与9-芴酮生成的叔醇中间体在酸性条件下环合形成螺二芴,再经Friedel-Crafts酰基化得到2-乙酰基螺二芴(3)和2,2-二乙酰基螺二芴(4);3或4与2-氨基二苯甲酮衍生物在酸催化下经过Friedlander缩合,制备了一系列具有荧光性的2-(4-取代苯基)喹啉-9,9'-螺二芴或2,2'-二(4-取代苯基)喹啉-9,9'-螺二芴,其结构经UV-vis,荧光光谱,1H NMR和元素分析表征.     

新型含芴基的富勒烯衍生物的合成

以2,7-二溴芴酮为起始原料,经Suzuki偶合、腙化和1,3-偶极环反应合成了3种新型的含芴基的富勒烯衍生物,其结构经UV-Vis,1H NMR,13C NMR,FT-IR和MALDI-TOF-MS表征。     

癸酸-十四烷酸二元体系的相变性能

以癸酸(CA)-十四烷酸(MA)二元体系的理论预测相图为指导, 测量了该体系不同组成超声波混合后的步冷曲线, 绘制了该体系的实验相图, 判断出最低共熔温度与组成范围; 采用DSC测试最低共熔组成的相变性能, 采用IR检测最低共熔组成300次热循环前后的波形变化. 实验结果表明, CA-MA二元体系最低共熔组成范围为(76%~82%)CA+(24%~18%)MA, 最低共熔温度为294.45 K, 最大过冷度为274.75 K, 相变过程中无分层现象; DSC和IR的测试结果表明, 组成为78%CA+22%MA的相变焓为149.02 J/g, 开始相变温度为292.80 K, 热稳定性好.     

Determination and measurement of solid–liquid equilibrium for binary fatty acid mixtures based on NRTL and UNIQUAC activity models

The estimation of solid–liquid phase equilibrium is important for the design, development, and operation of many industrial processes because of application in many manufacturing fields such as cosmetic, pharmaceutic, and biotechnology industries. In this work, we measured solid–liquid phase equilibrium of six fatty acid binary mixtures using the DSC technique and developed thermodynamic approaches for binary fatty acid mixtures to estimate melting temperatures as a function of mole fraction in solid–liquid phase equilibrium. Derivation of NRTL and UNIQUAC activity models was developed to predict melting temperatures and latent heat to achieve eutectic points of undecylic acid, pentadecylic acid, margaric acid, and stearic acid six pairwise binary mixtures. The fatty acids eutectic mixtures are appropriate for heat water systems, phase clothes, concrete, and other similar applications. The results showed low deviations from experimental data measured in this study.

     

Thermal behaviour of diclofenac, diclofenac sodium and sodium bicarbonate compositions

This work aims to investigate the thermal behaviour of diclofenac, diclofenac sodium, and NaHCO₃ both as single components and binary mixtures. In particular, the melting point and latent heat of fusion binary diagrams of the diclofenac sodium/diclofenac mixtures at different mole fraction compositions were investigated in order to gain information about the thermal behaviour of their solid mixtures. A good agreement between liquidus curves, calculated by the Schroeder-Van Laar equation from fusion enthalpies and temperatures, and the experimental results was found. For all binary compositions, an endothermic effect at 153°C, probably due to the eutectic fusion, is present.     

Thermal investigation of PEG 4000 — oxazepam binary system

A thermal study using DSC and Hot Stage Microscopy (HSM) was carried out to investigate the interaction in solid state of the binary system PEG 4000 — oxazepam, and to establish their phase diagram. The eutectic composition, which melting occurs at lower temperature as compared with the pure components, has been determined. The results obtained by DSC and HSM have indicated that PEG 4000 — oxazepam mixtures displays no obvious incompatibilities, and that the system shows a typical eutectic behaviour. However because of the closeness of the melting of PEG 4000 to the eutectic temperature, it was difficult to determine precisely the eutectic composition and temperature on the basis of DSC measurements alone. The use of heats of fusion corresponding to physical mixtures allowed an estimation of the eutectic composition at 6% w/w oxazepam. Additional information of temperature (57.6C) and composition (5–10% w/w oxazepam) of the eutectic was obtained by HSM using the contact method. This low melting temperature in this range of compositions offers advantages in terms of drug stability and easy manufacture.     

Binary Mixtures of Liquid Crystalline Ester Bismaleimides

Abstract

A binary system consisting of a chlorohydroquinone-based ester bismaleimide (3-Cl), T _m = 238°C, and a methylhydroquinone-based ester bismaleimide (3-Me), T _m = 251°C, was investigated for the purpose of improving processability by widening the nematic phase range before polymerization. Calculations based on the Schroeder-van Laar equation predicted a system eutectic composition of 41% 3-Me monomer and a eutectic temperature of 202°C. Experiments found the eutectic composition at 35% 3-Me and the eutectic temperature at 218.5°C. Discrepancies between experimental results and theoretical predictions are likely due to error in measured heats of fusion either due to impurities in the samples or due to the reactive nature of the components being considered. Thermal cycling was also found to have a significant melting point depression effect. While significant depression of the system melting point was achieved, polymerization still occurred immediately after melting in all systems evaluated. All mixtures could be polymerized from the nematic phase to yield a solid which retained the nematic orientation of the starting polymer melt.     

Thermal,spectroscopic, and dissolution studies of ketoconazole–Pluronic F127 system

One strategy for improving the dissolution of poorly water soluble drugs is to prepare solid dispersions such as binary mixtures with hydrophilic carriers. These mixtures are generally characterized by better solubility than those of the individual components from which they are formed. In the present study, solid dispersions of ketoconazole (KET) with Pluronic F127 (PLU) were prepared by the grinding method. Solid–liquid equilibria in the system being studied were investigated by differential scanning calorimetry. A phase diagram for the whole range of compositions was constructed. The investigation revealed that ketoconazole and Pluronic F127 form a simple eutectic system containing 4.4 % w/w of ketoconazole at the eutectic point. The results of Fourier transform infrared spectroscopy and X-ray powder diffractometry studies of obtained mixtures suggest that there is no drug-carrier interaction and both components are crystalline in the solid dispersion with the whole range of composition. The prepared mixtures show an appreciable improvement of the dissolution rate of KET in 0.5 % w/v sodium lauryl sulfate. The improvement of the dissolution rate of drug is additionally increased by effective solubilization.     

Synthesis and eutectic behavior of liquid crystalline copolyesters

A series of liquid crystalline copolyesters, derived from 1,4‐hydroxy‐benzoic acid (HBA), 6‐hydroxy‐2‐naphthoic acid (HNA), terephthalic acid (TA), and hydroquinone (HQ), were prepared; crystallization, melting and solid‐state structure of the copolyesters were studied by using differential scanning calorimetry (DSC) and wide‐angle x‐ray diffraction (WAXD). It was found that the variation of melting point of the copolyesters with increasing HBA mol % exhibits eutectic melting behavior at a constant mole ratio of HNA, and the extrapolated eutectic temperature decreases linearly with increasing HNA mol %. WAXD analysis of the copolyesters indicates that the d‐spacing related to three‐dimensional order increases first and then decreases with increasing HBA mol %. The increase of the d‐spacing, consistent with looser packing of chains, leads to the reduction of melting point and most likely accounts for the eutectic behavior observed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2171–2177, 2009     

Characterization of the crystallization behavior of the eutectic-forming binary system polyoxyethylene and glutaric acid. I. melting and crystallization behavior

The crystallization characteristics of the binary system polyoxyethylene (PEO)-glutaric acid were determined. From the extrapolated melting point depression data the heat of fusion for PEO is 2506 ± 200 cal/mole of repeat unit while the heat of solution for the glutaric acid amounts to 6.7 ± 1.2 cal/cm³. A melting point of 348 K is found for the high-molecular-weight PEO. A calorimetric glass-transition temperature for mixtures of the two components is relatively independent of the melt composition and appears at 217 K. A eutectic is observed whose composition and melting temperature depend on the nature of the PEO crystal phase.     

An approach to calculate solid–liquid phase equilibrium for binary mixtures

An approach is presented to calculate solid–liquid phase equilibrium for binary mixtures, using expressions for the temperature as a function of the molar fraction. For Margules model the expression gives explicitly the temperature, while for other liquid phase activity models an iterative procedure is required to calculate the temperature. The method is very easy to apply and it can be used for mixtures that have peritectic and eutectic points, or just a eutectic point. The approach was applied to five case studies with binary mixtures of fatty acids and triglycerides. The results were in good agreement with experimental data.     

Effects of several lanthanide trichloride hydrates on the melting behavior and spherulitic superstructure of poly(ethylene oxide)

Binary mixtures of poly(ethylene oxide) (PEO) with the trichloride hydrates of lanthanum, cerium, europium, terbium, and ytterbium have been studied with calorimetry, polarized optical microscopy, and infrared spectroscopy. Melting‐point depression of the PEO‐rich phase occurs in all cases. At sufficiently high concentrations of the low molecular weight lanthanide complex, crystallization of the polymer is absent. The lighter lanthanides with larger ionic radii, such as lanthanum and cerium, are more effective in suppressing PEO crystallization from solution or the molten state because they are more oxophilic. The spherulitic superstructure of PEO disappears at rather low concentrations of the lanthanide salts, between 2 and 8 mol % Ln³⁺. Lanthanum and terbium are most efficient at disrupting the formation of PEO spherulites, and europium is least efficient. Infrared spectroscopy identifies twisting and wagging vibrational absorptions of CH₂ groups in the polymer that are sensitive to the morphologies of these mixtures. Modifications of the PEO infrared absorbances in the presence of these five lanthanide salts correlate more closely with the presence or absence of major PEO melting, not the formation of a spherulitic superstructure. The phase behavior is rather simple, with no evidence of eutectic solidification upon cooling from the molten state. Multiple melting endotherms are observed in the differential scanning calorimetry heating traces of binary mixtures containing 8 mol % Yb³⁺ and between 10 and 20 mol % Eu³⁺, but the concentration dependence of these first‐order endothermic transitions is not characteristic of eutectic phase behavior. The presence of trivalent cations, such as Eu³⁺ or Yb³⁺, in these complexes perturbs the crystallization kinetics of PEO upon cooling from the molten state, as well as the melting behavior upon heating. Ion–dipole or electrostatic interactions between the lanthanide cation and the ether oxygen of PEO might alter the surface free energy at the periphery of the crystalline lamellae and perturb the chain‐folding characteristics of PEO. Consequently, coupling between the amorphous matrix and the PEO crystallites is strengthened, and this provides stability for the existence of multiple‐chain‐folded crystals composed of rather thin lamellae that could be responsible for multiple melting behavior. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2200–2213, 2003