Sorption and transport of aqueous salt solutions of acetates, acetic and monochloroacetic acids in polyurethane

Sorption, diffusion and permeation of aqueous salt solutions of acetates of sodium, calcium and nickel in addition to acetic and monochloroacetic acid solutions have been investigated in the temperature interval of 25–60°C in a commercial polyurethane. An immersion/weight-gain experiment was used to study sorption and diffusion of 0.15, 0.5 and 1.0 M solutions of acids and salts. Permeability coefficients were estimated from sorption and diffusivity coefficients. From the temperature dependence of transport coefficients, the Arrhenius activation parameters have been estimated and the results were used in the discussion of transport mechanisms. The diffusivity of monochloroacetic acid solution was smaller but its solubility was higher than all the solutions used in this research. For comparative purposes, the transport of water was also studied.     

Equation of state for the systems containing aqueous salt: Prediction of high pressure vapor-liquid equilibrium

An equation of state (EOS), which is based upon contributions to the Helmholtz energy, is presented for systems containing aqueous electrolyte solutions at high pressure. The Peng-Robinson equation of state is used to provide the Helmholtz energy of a reference system. The electrolyte terms consist three terms containing a modified Debye-Hückel term for long-range electrostatic interactions, the Born energy contribution for electrostatic works and a Margules term for short-range electrostatic interactions between ions and solvents. The binary and ternary interaction parameters of the equation of state are obtained by experimental osmotic coefficient data. Systems that were studied here are (water+ NaCl+SC-CO₂), (water+NH₄Cl+SC-CO₂), (water+Na₂SO₄+SC-CO₂) and (water+methanol+NaCl+SC-CO₂). It is found that the proposed equation of state is able to accurately represent the experimental data over a wide range of pressure, temperature and salt concentration.     

Synthesis and characteristics of aqueous reactive urethane oligomer containing sulfoisophthalate sodium salt

This research studied urethane oligomers, which contains the sulfonic acid group and different reactive groups. First, the transesterification of dimethyl 5‐sulfoisophthalate sodium salt were performed with ethylene glycol or polyethylene glycol of different molecular weights to produce PEG soft chains possessing sulfonic acid group. Subsequently, isophorone diisocyanate used as a hard chain was connected to the two terminals of the sulfonated diols, which finally were blocked by methyl ethyl ketoxime or hydroxyethyl methacrylate or 2, 3‐Epoxy‐1‐propanol to form three kinds of aqueous reactive urethane oligomers (MSE, HSE, and OSE). The MSE oligomer had the greatest particle diameter, particle variance, and streaming current readings; the HSE oligomer, and the OSE oligomer had the second large and the smallest readings of the aforementioned measurements, respectively; whereas the contact angle and surface tension appeared with an opposite trend. Within the thermal properties of oligomer, the T_g of oligomer followed the trend: OSE < HSE < MSE; however, T_m and ΔH show an opposite tendency. With regard to the reactivity of the oligomers toward PET fabric, the add‐on for the variety of oligomers was in the quantity order of MSE > HSE > OSE series, and the washing durability was rated in the order of HSE > MSE > OSE series. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Blends of metal acetates and polyurethanes containing pyridine groups

Two series of segmented polyurethanes based on 3/2/1 and 2/1/1 molar ratios of methylene diphenyldiisocyanate (MDI), N,N-bis (2-hydroxyethyl) isonicotinamide (BIN), and poly(tetramethylene oxide) (PTMO, MW = 1000) were synthesized and blended with different metal acetates. The thermal behavior and mechanical properties of the pyridinecontaining polyurethane precursors and their blends were characterized by DSC, DMTA, and tensile testing. The results suggest that coordination between pyridine groups in the hard segments and the metal ions in the acetates improves hard-domain cohesion and phase separation and, subsequently, has an effect on mechanical properties. The varying ability of the pyridine group to coordinate with different cations results in different extents of phase separation. The interaction of pyridine with Ni or Cu (II) is much stronger than with Zn. It is shown that coordination interactions can be a driving force for phase separation and hard-domain aggregation in multiblock copolymer systems. Two different morphologies are proposed for polyurethanes of differing stoichiometry to explain the differences in the results from DMTA and tensile testing. © 1994 John Wiley & Sons, Inc.     

Influence of added salt on dynamic viscoelasticity of carboxymethylcellulose aqueous systems

Using three series of sodium carboxymethylcellulose (NaCMC) in the range of the degree of substitution (the average number of carboxymethyl groups/glucose unit) from 0.5 to 1.3, weight-average molecular weight M_w was determined by light scattering in solution of triethylenediamine cadmium hydroxide (cadoxene). It was found that the relation between M_w and the limiting viscosity number [η] in 0.1 N sodium chloride (NaCl) aqueous solution can be represented by Staudinger's equation. Dynamic viscoelasticity of aqueous disperse systems of NaCMC with various added salts was measured by means of a cone-and-plate rheometer. If the concentration of added salt is less than the concentration at which polymer begins to salt out, frequency dependence curves of the dynamic modulus, which is measured at various salt concentrations, can be superposed into a master curve by horizontal shift only. The shift factor depends on the salt concentration and the kind of salt.     

Solid-liquid equilibria in concentrated aqueous salt solutions—systems with a common ion

A thermodynamic correlation is presented for solid-liquid equilibria in concentrated aqueous salt systems containing a common ion. It is assumed that no solid solutions are formed, although the solid phase can be a pure salt, a multiple salt or a hydrate. Predictions of solid-liquid equilibria in multicomponent systems are made using parameters calculated from solid-liquid equilibrium data for the constituent binary and ternary systems.Parameters are given for the prediction of solid-liquid equilibria in the aqueous system containing Na⁺, K⁺, Mg⁺⁺, NO^?₃, Cl^?, SO^--₄ from 0–50°C. These parameters correlate the available solid-liquid equilibrium data for ternary systems with an error in liquid-phase composition of less than 2 grams salt/100 grams H₂O. Errors are similar in the estimation of solid-liquid equilibria in four-component systems such as NaNO₃-NaC1-Na₂SO₄-H₂O.     

有机合成中含吡啶的试剂

吡啶可以和卤素、硝基四氟化硼盐、三氧化硫、硼烷及三氧化铬反应，形成一些有用的有机试剂。     

Extended UNIQUAC model for correlation and prediction of vapor-liquid-liquid-solid equilibria in aqueous salt systems containing non-electrolytes. Part B. Alcohol (ethanol, propanols, butanols)-water-salt systems

The Extended UNIQUAC model for electrolyte solutions is an excess Gibbs energy function consisting of a Debye-Hückel term and a term corresponding to the UNIQUAC equation. For vapor-liquid equilibrium calculations, the fugacities of gas-phase components are calculated with the Soave-Redlich-Kwong equation of state. The model only requires binary, temperature-dependent interaction parameters. It has previously been used to describe the excess Gibbs energy for aqueous electrolyte mixtures and aqueous electrolyte systems containing methanol. It has been found to be an adequate model for representing solid-liquid-vapor equilibrium and thermal property data for strongly non-ideal systems. In this work, the model is extended to aqueous salt systems containing higher alcohols. The calculations are based on an extensive database consisting of salt solubility data, vapor liquid equilibrium data, and liquid-liquid equilibrium data for solvent mixtures and for mixed solvent-electrolyte systems.The application of this model to represent the vapor-liquid-liquid-solid equilibria in aqueous systems containing various non-electrolytes (ethanol, 1-propanol, 2-propanol, 1-butanol, 2- butanol, 2-methyl 1-propanol, 2-methyl 2-propanol) and various ions (Na⁺, K⁺, NH₄⁺, Cl⁻, NO₃⁻, SO₄²⁻, SO₃²⁻, HSO₃⁻, CO₃²⁻, and HCO₃⁻) shows the capability of the model to accurately represent the phase behavior of these kinds of systems.     

Application of peng-Robinson equation to high-pressure aqueous systems containing gases and sodium chloride

A novel approach is proposed for modeling vapor-liquid equilibria in systems containing aqueous NaCl and supercritical gases. The Peng-Robinson equation of state is used for all species, with the salt treated as a hypothetical liquid component. To correctly model the highly non-ideal liquid solution, a two-fluid model is used for the mixing rules in the equation of state. Effective pure-component parameters are reported for NaCl as well as binary interaction parameters for all possible binaries. Representation of high-pressure phase equilibria data show good agreement with experimental data. The principal advantage of this approach is the ability to treat high pressure systems containing non-volatile salts, while maintaining the simplicity of a cubic equation of state.     

A novel polymeric gel electrolyte systems containing magnesium salt with ionic liquid

A new polymeric gel electrolyte system consisting of poly(ethylene oxide)-modified polymethacrylate (PEO-PMA) with organic ionic liquid dissolving magnesium salt, Mg[(CF₃SO₂)₂N]₂, has been developed. The ionic conductance and electrochemical properties of the gel films were investigated. The obtained gel film was self-standing, transparent and flexible with sufficient mechanical strength. Thermal analysis of the gel film showed that it is homogeneous and amorphous over a wide temperature range. The highest conductivity, ca. 3.5 mS cm⁻¹ at 60 °C, was obtained for the polymeric gel containing 80 wt.% of the liquid component that consists of 80 mol% of EMITFSI (1-ethyl-3-methylimidazolium bis(trofluoromethylsulfonyl)imide) and 20 mol% of Mg[(CF₃SO₂)₂N]₂. The sort of the ionic liquid affected much on the ionic conductivity of the gel. The dc polarization of a Pt/polymeric gel electrolyte/Mg cell proved that the magnesium ion (Mg²⁺) can mobile in the present polymeric gel system.     

季膦盐离子液体/表面活性剂/盐双水相的性质及萃取效果研究

向水相中加入有机物或盐, 在一定组成范围内, 可以形成密度不同的两相, 即双水相, 目前在生物萃取领域有广泛的应用。离子液体/表面活性剂体系的双水相体系符合绿色化学的要求, 而且目前研究尚不多见。采用离子液体四丁基膦氯化铁盐、十四烷基三丁基膦氯化铁盐（[P4444]FeCl₄、[P44414]FeCl₄）和两种表面活性剂十二烷基硫酸钠、十二烷基苯磺酸钠（SDS、SDBS）及柠檬酸钠混合形成双水相体系, 并绘制了[P4444]FeCl₄（[P44414]FeCl₄）/SDS（SDBS）/盐4个体系的相图, 用粒度测试研究发现, 双水相的上相粒度约为60~80 nm, 下相粒度太小而未能检测出来。使用紫外-可见分光光度法研究了双水相体系对不同性质染料的萃取效果。结果表明, 离子液体的疏水链长度和表面活性剂疏水链上存在苯环与否都对体系中双水相的区域产生影响。4个双水相体系都对水溶性染料有很好的萃取作用, 但是对油溶性染料萃取效果不佳。此项研究促进了离子液体在化学分离领域的开发利用。     

Partitioning of lysozyme in aqueous two-phase systems containing ethylene oxide-propylene oxide copolymer and potassium phosphates

Lysozyme partitioning in EO₅₀PO₅₀/potassium phosphate aqueous two-phase systems (ATPS) was studied. In the work, the influence of EO₅₀PO₅₀, potassium phosphate and sodium chloride concentration in the ATPS on lysozyme partition coefficient and separation yield was examined. In addition, the influence of the pH of potassium phosphate solution was also investigated. A Box–Behnken design was defined, and response surface models for the partition coefficient K and percentage yield of the enzyme in the top phase Y were calculated. Among the examined factors, the NaCl concentration had the highest influence on lysozyme separation parameters. This influence can be explained mainly by the hydrophobic interactions between the protein and the phase-forming components. A maximum partition coefficient K_L1, yield Y_L1 and Y_L2 were predicted for EO₅₀PO₅₀, potassium phosphate and NaCl concentrations of 17.40, 22.67% and 0.85 mol/l, respectively, and for pH 9.0. A good agreement was obtained between the experimental and the predicted results.     

Dispersion of Cu2O particles in aqueous suspensions containing 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt

Effect of 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt's addition upon Cu₂O dispersion properties is studied to clarify dispersant's role in colloidal properties change and its underlying stabilization mechanism, and to quantify processing conditions for the oxide. Dispersing effectiveness was studied through adsorption, rheological and electrophoretic measurements, using as-received and surface charge modified Cu₂O particles. Maximum solid loading attained without dispersant was 73 wt.% (31 vol.%), with corresponding viscosity of 152.5 ± 7.3 Pa s. Addition of dispersant resulted in viscosity between 21.0 Pa s and 5.4 Pa s. No isoelectric point was found for as-received particles’ suspensions nor for dispersed suspensions, with particles presenting negative surface charge in all studied pH range, from pH 4 to 10. Adsorption of the organic molecule caused an absolute downshift of 8–25 mV of the electrophoresis curve. Dispersant/Cu₂O interaction was assessed through FTIR analysis. Attained results suggest that, at the natural suspensions pH, dispersant-modified Cu₂O suspensions are stabilized through inner-sphere complexation mechanism, resulting in high dispersion ability.     

Modifications induced by zinc,cadmium and mercury acetates on hexokinase in aqueous solutions

Preferential interactions of hexokinase with solvent were studied in aqueous solutions of Zn²⁺, Cd²⁺ and Hg²⁺ acetates. In addition, these preferential interactions were correlated with protein solubility in the solvent media and the influence of salts on the tertiary structure of hexokinase using viscometric studies. The viscometric results show that hexokinase can undergo a conformational change at 2·5mM of Zn²⁺ and Cd²⁺ salts, whereas the effect of Hg²⁺ acetate on hexokinase is evident at ten times smaller concentrations. The interaction parameter is always positive for all the salts studied, indicating that interaction of the salt and protein is thermodynamically unfavourable, although this effect is lower for the Zn²⁺ salt. The transfer free energy parameter and solubility data show that for hexokinase zinc acetate is a salting-in agent, mercury acetate is a salting-out agent and cadmium acetate cannot be clearly classified. © 1998 Society of Chemical Industry.     

含钙三元氯化物体系相图计算与熔盐热稳定性

为寻求太阳能热利用高温传热储热材料,以盐湖资源为原料,提出分支/分区相图计算方法,设计NaCl-CaCl₂-KCl和KCl-CaCl₂-MgCl₂熔盐传热储热材料。基于正规溶液模型,以不同分支不同相互作用系数,计算了5个边界体系相图,实现用正规溶液模型计算含化合物体系复杂相图。含化合物KCl-CaCl₂和KCl-MgCl₂体系及3个不含化合物二元体系的计算相图与实验相图十分吻合。以分区域方法计算三元体系相图,预测出5个低共熔点来指导熔盐制备。采用差示扫描量热法测试并验证熔盐最低共熔点,确定其工作温度下限;以质量损失实验,确定其工作温度上限。结果表明,钠钾钙和钾镁钙氯化物熔盐能在550~850℃和480~700℃内稳定运行,可用作高温传热储热流体。     

Design of deicing reagents based on alkali and alkaline-earth metals and ammonium formates, acetates, and nitrates

Phase equilibria in binary, ternary, and quaternary water-salt systems containing sodium, potassium, magnesium, calcium, and ammonium nitrates, formates, and acetates have been studied in the temperature range of 0 to ?70°C, and polytherms of the fusion of ice have been plotted. A series of binary and ternary salt compositions that form low-temperature eutectics with ice, which are promising as deicing reagents, has been determined. The corrosion activity of the most promising compositions relative to metals and alloys, as well as cement concrete pavements, has been determined. Corrosion inhibitors have been chosen.     

The performance of epoxy coatings containing polyaniline (PANI) nanowires in neutral salt,alkaline, and acidic aqueous media

PANI/epoxy coatings have great promise applications in the industry as the metal corrosion protection coating, and their performance directly determines the life span of the coating and equipment durability. In this study, the performance of epoxy coatings with and without PANI nanowires immersed in 12 wt% NaCl, 5 wt% HCl, and 5 wt% NaOH solutions at different temperature were investigated for the first time. The performance and the degradation reactions of the coating cooperated with PANI nanowires were characterized by the variety of techniques and methods, including ultraviolet–visible spectrophotometry (UV–vis), field emission scanning electron microscopy (SEM), Attenuated Total Reflectance-Fourier transform Infrared spectroscopy (ATR-FTIR), and thermogravimetric analysis (TGA). The experiment results indicated that the failure mechanism of the different coatings varied with the different temperatures and solutions. Electrochemical impedance spectra (EIS) results showed that an appropriate content of PANI nanowires improve the protection performance of epoxy coatings in 12 wt% NaCl, 5 wt% HCl, and 5 wt% NaOH solutions, which is attributed to the passivation ability and shielding effect of PANI nanowires.