Experimental study of the density and viscosity of polyethylene glycols and their mixtures at temperatures from 293 K to 473 K and at atmospheric pressure

A new apparatus to measure simultaneously the density and viscosity of liquids has been designed and constructed based on the hydrostatic weighing and falling-body principles. The density and viscosity of monoethylene glycol (MEG), diethylene glycol (DEG), and triethylene glycol (TEG) and their binary, (50%MEG + 50%DEG), (50%MEG + 50%TEG), (50%DEG + 50%TEG), and ternary (33.33%MEG + 33.33%DEG + 33.34%TEG) mixtures have been measured over the temperature range from 293 K to 473 K and at atmospheric pressure. The expanded uncertainty of the density, pressure, temperature, and viscosity measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 0.15% to 0.30%, 0.05%, 0.06 K, and 1.5% to 2.0% (depending on temperature and pressure ranges), respectively. The theoretically based Arrhenius–Andrade and Vogel–Tamman–Fulcher type equations were used to describe the temperature dependence of measured viscosities for pure polyethylene glycols and their mixtures.     

VTF to arrhenius crossover in temperature dependence of conductivity in (PEG)xNH4ClO4 polymer electrolyte

We have studied the temperature variation of conductivity and ¹H NMR linewidth of (PEG)_xNH₄ClO₄ (x = 20, 30, 46, 100, 200, & 1000) polymer electrolyte systems. The temperature dependence of the conductivity shows two distinct behaviors, the low temperature VTF dependence crossing over to Arrhenius dependence at higher temperatures. The departure from the VTF behavior is found to be composition dependent. NMR spectra indicate the presence of large fractions of crystalline regions that start to melt around the crossover temperature. We understand the deviation from the VTF behavior as a consequence of this crystalline to elastomer transition. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1201–1209, 1998     

具有多重玻璃化转变的梳状聚合物的合成,表征和导电性：侧链 …

以分子量为５５０的聚乙二醇单甲醚为侧链,苯乙烯／马来酸酐共的为骨架,合成了苯乙烯／马来酸酐共聚物多缩乙二醇酯。用红外光谱、元素分析、ＤＳＣ、热失重等方法,对合成条件、产物结构和性能进行了研究。结果表明：反应严格按照反应方程进行,精制产物是非晶的梳状聚合物。玻璃化转变温度为３０．６８℃,分解温度为１２０℃。对动态这性能及其锂盐复合物离子导电性进行了研究,表明α转变温度和β转变温度分别是２８℃他－４７     

交替马来酸酐共聚物多缩乙二醇酯盐络合物的离子传导性

交替马来酸酐共聚物多缩乙二醇酯盐络合物的离子传导性丁黎明，林云青，周子南，王佛松（中国科学院长春应用化学研究所，长春，１３００２２）关键词高分子固体电解质，离子电导率，玻璃化转变温度，离子传输，ＶＴＦ方程１９７３年，Ｐ．Ｖ．Ｗｒｉｇｈｔ等人［１］首次...     

以脲和硫氰酸铵为主体的固体电解质的研究

制得以脲和硫氰酸铵为主体的固体电解质,其室温电导率可达到４．３５×１０－２Ｓ·ｃｍ－１,比以脲和硫脲为主体固体电解质的电导率６．８４×１０－３Ｓ·ｃｍ－１提高了一个数量级。实验发现,影响电导率的因素主要有组成、温度和高分子。ＤＴＡ表明该电解质为非晶态固熔体,其导电性质既不服从Ａｒｈｅｎｉｕｓ方程,又不服从ＶＴＦ方程     

短链羟基甲基咪唑离子液体的合成与电化学性能

通过2-(2-氯乙氧基)乙醇和2-溴乙醇分别与1-甲基咪唑反应,合成乙醇基甲基咪唑溴(EMIMBr)和乙氧基乙醇基甲基咪唑氯(EEMIMCl)2种羟基咪唑离子液体,用1H NMR和FT-IR表征结构,TG和DSC进行热性能测试,并研究了其电化学性能.结果表明,羟基类咪唑离子液体具有高的热稳定性,这种含醚氧键和羟基的短链离子液体有利于电导率的提高,导电机理符合Vogel-Tmman-Fulcher (VTF)方程.乙醇基甲基咪唑溴和乙氧基乙醇基甲基咪唑氯的室温电导率分别为1.2×10-4和1.7×10-4 S/cm.对于碳酸丙二醇酯、乙氧基乙醇基甲基咪唑氯和钾盐体系,室温电导率最高可达3.82×10-3 S/cm.乙氧基乙醇基甲基咪唑氯的电化学窗口为3.4V.     

Specific ionic conduction in poly[oligo (oxyethylene glycol) methacrylate] (PMEO)–Li salt complexes under high‐pressure CO2

We measured the ionic conductivity of amorphous poly[oligo (oxyethylene glycol) methacrylate] (PMEO)–lithium salt complexes under a CO₂ pressure varying from 0.1 to 20 MPa. The pressure dependence of the conductivity was positive, and the conductivity was higher than that under an inert gas such as N₂. The ion‐conductive behavior has been modeled using both the Vogel–Tammann–Fulcher (VTF) equation and activation volume theory. The calculated parameters of the VTF equation show that CO₂ that had permeated into the PMEO matrix acts as solvent molecules to dissolve ions and lower the glass transition temperature at high pressures. The ionic conduction in PMEO complexes under high‐pressure CO₂ was scarcely related to the VTF parameters and activation volume equations. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3151–3158, 2005     

二元混合离子液体的电导率与离子间的缔合作用

在293.15-323.15 K范围内, 测定了13种常见离子液体及其25组混合体系的电导率. 利用Vogel-Tammann-Fulcher (VTF)方程对电导率数据进行拟合, 并通过方程式中的拟合参数分析了离子液体混合后其阴阳离子间缔合作用的变化规律. 结果表明,在相同温度下, 离子液体的阳离子侧链越短,阴离子电荷越分散, 阴阳离子间的氢键作用力越弱,离子液体的电导率越大, 其中阴离子的影响比阳离子更明显.混合离子液体中离子间的缔合作用不仅与阴阳离子的种类有关,而且与混合物的组成有关.     

Poly(ethylene oxide)-polyurethane/poly(acrylonitrile) semi-interpenetrating polymer networks for solid polymer electrolytes: vibrational spectroscopic studies in support of electrical behavior

Studies on solid polymer electrolyte systems based on semi-interpenetrating polymer networks of poly(ethylene oxide)-polyurethane and poly(acrylonitrile) (PEO-PU/PAN) doped with lithium trifluoromethanesulfonate (LiCF₃SO₃) is reported. Room temperature FT-IR analysis indicates a salt solvation process that occurs predominantly in the polyether segments of the semi-IPNs and incorporation of salt is also seen to favor a morphological change in the matrix with a transition from semi-crystalline to amorphous phase. From the relative band areas a critical concentration (C_c) of salt can be identified where concentration of ionic species, morphology and amount of transient crosslinks is optimal to impart maximum conductivity, which is in agreement with the room temperature conductivity results. Thermal analysis of the semi-IPN lends further support to this observation. The temperature dependence of conductivity is found to follow the Arrhenius behavior at low temperatures (∼ upto 328 K) and VTF dependence at higher temperatures. This crossover in temperature dependent conductivity is attributed to the change in the phase morphology of the semi-IPNs beyond the crystalline melting temperature (T_m1) of the polyether segments.     

玻璃化转变在室温附近的一种新型梳状聚合物的合成和表征——侧链分子量为550的聚乙二醇单甲醚

以分子量为５５０的聚乙二醇单甲醚为侧链,苯乙烯／马来酸酐共聚物为骨架,合成了苯乙烯／马来酸酐共聚物多缩乙二醇酯,用红外光谱、元素分析、ＤＳＣ、热失重等方法,对合成条件、产物结构和性能进行了研究。结果表明：反应严格按照反应方程进行,精制产物是非晶的梳状聚合物。玻璃化温度为３０．６８℃,分解温度为１２０℃。对动态力学性能及其锂盐复合物离子导电性进行研究表明α转变温度和β转变温度分别是２８℃和－４７．７℃。电导率与温度的依赖关系符合ＶＴＦ方程。室温电导率最高可达４．２×１０－５Ｓ／ｃｍ。