Viscosity and Thermodynamics of Viscous Flow of 1-propanol with Aniline,N-methylaniline and N,N-dimethylaniline

Abstract

Viscosities of the systems, 1-propanol + aniline, 1-propanol+N-methylaniline and 1-propanol+N,N-dimethylaniline have been measured in the temperature range 294.15 to 323.15K for the whole range of composition. The viscosities have been plotted against mole fraction of anilines. The viscosity-composition curves show minima, though not well-defined, in highly rich, moderately rich and moderately poor regions of 1-propanol respectively for 1-propanol + aniline, 1-propanol + N-methylaniline and 1-propanol +N,N-dimethylaniline systems. The excess viscosities have been found to be negative for all the systems throughout the whole composition and plotted against mole fraction of anilines. The thermodynamic activation parameters, such as, enthalpies, entropies and free energies and their excess values have been evaluated. The excess free energies have been found to be negative for all the systems and over the whole range of composition. The excess free energies have been plotted against the mole fraction of anilines. The viscosities, excess viscosities and excess free energies have been explained by assuming that the associated compounds, aniline, N-methylaniline and 1-propanol, are dissociated into smaller units in the solution systems by the rupture of H-bonds.     

Excess enthalpies of binary solvent mixtures of N,N-dimethylacetamide with aliphatic alcohols

The excess enthalpies H _m ^E of binary solvent mixtures of N,N-dimethylacetamide with methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and t-butanol have been measured with a flow microcalorimeter at 40°C. The excess enthalpies increase as the length of the alkyl chain of the primary alcohol increases. The values for methanol are negative, those for ethanol change sign, and those for 1-propanol, and more clearly those for 1-butanol, are positive. The mixtures of the secondary and the tertiary alcohol exhibit mainly positive values of H _m ^E . Solute-solute and solute-solvent interactions in these mixtures are discussed on the basis of the results.     

Excess Molar Volume of 1-propanol+Aniline, +N-methylaniline, +N,N-dimethylaniline

Abstract

Densities of the systems, 1-Propanol(P)+aniline(A), 1-Propanol(P)+N-Methylaniline (NMA) and 1-Propanol(P)+N,N-Dimethylaniline(DMA) have been measured from 21°C to 50°C at an interval of 5°C. The excess molar volumes, V ^E, of the systems, P+A and P +NMA have been found to be negative for the whole range of composition. V^E of the system P+DMA has also been found to be negative, except in DMA-rich region where small positive excess volume is observed. The negative excess volume has been explained primarily in terms of strong specific interaction and size difference of unlike molecules. The magnitude of the negative excess volumes of these systems is of the order, P+A > P + NMA > P + DMA, which has been strongly influenced by steric effect due to CH₃ group attached to N-atom of NMA and DMA. In the highly rich region of DMA in P+DMA system the small positive excess volume is accounted for by the steric effect and breaking up of H-bond of 1-Propanol.     

Enthalpy of interaction of some electrolytes with 2-methyl-2-butanol in wate at 25°C

Enthalpies of mixing in water of 2-methyl-2-butanol with several electrolytes (alkali-metal halides, tetra-n-alkylammonium bromides, Ph₄PCl, Ph₄AsCl and NaPh₄B) have been determined by flow microcalorimetry at 25°C. Enthalpic pair interaction coefficients, h_NE, of the virial expansion of the excess enthalpy were calculated. All coefficients are positive and increase as the anionic size increases in anionic series of alkali-metal halides. A linear correlation between h_NE and the number of carbon atoms in the apolar group of R₄NBr is observed. For alkali-metal halides coefficients h_NE depend mainly on the partial desolvation of halides, and for hydrophobic electrolytes both the partial desolvation of halide ions and hydrophobic interaction are the leading factors in the value of h_NE.     

Thermodynamics of binary mixtures: Volumes,heat capacities,and dilution enthalpies for then-pentanol+2-methyl-2-butanol system

The densities, heat capacities, and dilution enthalpies ofn-pentanol+2-methyl-2-butanol mixtures have been measured, in many cases as a function of temperature, over the complete mole fraction range. Excesses thermodynamic properties, apparent and partial molar heat capacities, volumes and expansibilities were derived. The concentration and temperature dependences of these functions are discussed in terms of the variations of the structure of the system caused by the participation of the two alcohol molecules (with quite different steric hindrance of the alkyl chain around the-OH group) in the dynamic intermolecular association process through hydrogen bonding.     

Excess enthalpies of binary solvent mixtures of N-methylacetamide with aliphatic alcohols

The molar excess enthalpies H _m ^E of binary solvent mixtures of N-methylacetamide with methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and t-butanol have been measured with a flow microcalorimeter at 40°C. The excess enthalpies are negative for methanol and positive for the other alcohols over the whole composition range, except for t-butanol which exhibits a sigmoid curve with a deep minimum at low mole fractions of the amide. The values for the primary alcohols increase in the order methanol < ethanol < 1-propanol < 1-butanol. The partial molar excess enthalpies have also been evaluated. Intermolecular interactions in these mixtures are discussed through comparison of the results with those for the corresponding binary mixtures of N,N-dimethylacetamide.     

Vapor-phase synthesis of V-butylaniline from aniline and 1-butanol over Cu/SiO2 catalyst

The Cu/SiO2 catalyst prepared by incipient wetness method exhibited very high activity and selectivity for the vapor-phase synthesis of JV-butylaniline from aniline and 1-butanol. When Cu loading was 0.70 mmol/g-SiO2 and the catalyst precursor was calcined at 500 ℃, 1-butanol conversion reached 99%, and the selectivity of JV-butylaniline exceeded 97%.     

Vapor-phase synthesis of N-butylaniline from aniline and 1-butanol over Cu/SiO2 catalyst

The Cu/SiO2 catalyst prepared by incipient wetness method exhibited very high activity and selectivity for the vapor-phase synthesis of N-butylaniline from aniline and 1-butanol. When Cu loading was 0.70 mmol/g-SiO2 and the catalyst precursor was calcined at 500 ℃, 1-butanol conversion reached 99%, and the selectivity of N-butylaniline exceeded 97%.     

Excess enthalpies of binary mixtures of 2-ethyl-1-butanol with hexane isomers

Molar excess enthalpies, measured at 298.15 K in a flow microcalorimeter, are reported for binary mixtures of 2-ethyl-1-butanol with the five isomeric hexanes. The results are compared with previously published excess enthalpies for mixtures of 1-hexanol and 2-methyl-1-pentanol with the same hexane isomers.     

Excess enthalpies of binary mixtures of 2-methyl-1-pentanol with hexane isomers

Kimura, F. and Benson, G.C., 1982. Excess enthalpies of binary mixtures of 2-methyl-1-pentanol with hexane isomers. Fluid Phase Equilibria, 8:107-112.Molar excess enthalpies, measured in a flow microcalorimeter, are reported for binary mixtures of 2-methyl-1-pentanol with n-hexane and its four isomers. There is a roughly linear correlation between the results for equimolar mixtures and the mean number of gauche conformations of the isomer.     

Enthalpies of transfer of 2-methyl-2-propanol from water to mixtures of water with methanol,ethanol and 1,4-dioxane

The enthalpies of transfer of 2-methyl-2-propanol (TBA) from water to mixtures of water with methanol, ethanol and 1,4-dioxane have been measured. The data are considered in terms of recently developed theory, and it is found that the enthalpies of transfer can be reproduced quantitatively over most of the composition range in each solvent system. The parameters recovered from the analyses indicate that the net effect of TBA on the solvent structure is a breaking of solvent-solvent bonds and that TBA is preferentially hydrated in the aqueous alcohol systems, but randomly solvated in the water+1,4-dioxane system. It is also found that the model parameters for TBA solvation in the alcohol systems are independent of the alcohol.     

酵母脂肪酶催化拆分外消旋2-甲基-1-丁醇

近年来,水相中酶催化拆分外消旋酯制备具有光学活性的手性酸或醇,其酶在非水体系的研究取得了重要进展,已发展到用含有微水或几乎无水的有机溶剂取代最初的水相,这样既可避免水参与有关的副反应,又有利于酶的回收。而且酶在某些有机溶剂中比在水中稳定,不会由于微生物污染而使酶失活。脂肪酶能够催化酯的     

Solubility of carbon dioxide in aqueous solution of 2-amino-2-methyl-1-propanol and piperazine

In this work, new experimental results of the vapour-liquid equilibrium (VLE) of CO₂ in aqueous 2-amino-2-methyl-1-propanol (AMP) and piperazine (PZ) have been presented in the temperature range of 298-328 K and PZ concentration range of 2-8 mass%, keeping the total amine concentration in the solution at 30 mass%. The partial pressures of CO₂ were in the range of 0.1-1450 kPa. A thermodynamic model was developed to correlate and predict the VLE of CO₂ in aqueous AMP + PZ. The electrolyte nonrandom two liquid (ENRTL) theory has been used to develop the VLE model for the quaternary system (CO₂ + AMP + PZ + H₂O) to describe the equilibrium behaviour of the solution. The experimental data from this work and data available in the literature were used to regress the ENRTL interaction parameters. The model predictions are in good agreement with the experimental data of CO₂ solubility in aqueous blends of this work as well as those reported in the literature. The current model can also predict speciation, heat of absorption, pH of the CO₂ loaded solution, and amine volatility.     

Molecular interactions in 1-pentanol +2-methyl-2-butanol mixtures: Static dielectric constant,viscosity and refractive index investigations at 5, 25 and 45°C

Static dielectric constants, refractive indices and viscosities of 1-pentanol +2-methyl-2-butanol mixtures were measured at 5, 25 and 45°C. The results show that the mixing of the two isomers modifies the polarizability and the resistence of viscous flow of the system depending on the composition and temperature. Short range intermolecular interactions producing hetero-alcohol open dimers are considered.     

An FTIR spectroscopic study and quantification of 2-amino-2-methyl-1-propanol,piperazine and absorbed carbon dioxide in concentrated aqueous solutions

This study reports the investigation of carbon dioxide (CO₂) absorption into an amine blend solution of 2-amino-2-methyl-1-propanol (AMP) and piperazine (PZ). The reaction in the liquid phase between CO₂ and the amines were qualitatively and quantitatively monitored by Fourier Transform Mid-Infrared spectroscopy (mid-FTIR). A multivariate partial least square regression (PLS2) model was obtained to quantify free or non-reacted AMP and PZ and absorbed CO₂ in all chemical forms, i.e. no differentiation was made into carbonates or carbamates. The calibration model was constructed using a single wide region and 270 calibration samples. The concentration of AMP, PZ and CO₂ from 568 samples were simultaneously predicted with low relative errors.     

Kinetic-catalytic determination of traces of iron by the oxidative coupling reaction of 3-methyl-2-benzothiazolinone hydrazone with N,N-dimethylaniline

A new kinetic-catalytic method by the initial rate procedure for the determination of nanogram level of iron(III) is developed, which is based on its catalytic effect on the oxidative coupling of 3-methyl-2-benzothiazolinone hydrazone (MBTH) with N,N-dimethylaniline (DMA) to form an indamine dye (λ_max=590 nm) in the presence of hydrogen peroxide. Iron(II) is also determined, being oxidized to iron(III) by hydrogen peroxide. Calibration graphs obtained by the initial rate method are linear in the range 1–1000 ng ml⁻¹ Fe and as low as 10⁻⁸ M Fe(II, III) can easily be determined. The relative standard deviations are 6.6, 2.5 and 1.5% for ten determinations of 1, 20 and 60 ng ml⁻¹ of Fe(III), respectively. The method is applicable to the determination of iron in natural waters without preconcentration and separation.     

Thermodynamics of binary liquid mixtures of cyclopentane with 2-propanol, 1-butanol and 2-butanol at different temperatures

Densities and speeds of sound of the cyclopentane with 2-propanol, 1-butanol and 2-butanol are measured over the whole composition range at different temperatures in the range 288.15–308.15 K and atmospheric pressure using Anton Paar DSA 5000 densimeter. The experimental densities and speeds of sound have been used to calculate excess molar volumes, excess molar isentropic compressibilities and excess intermolecular free length. The partial molar volumes and apparent molar volumes at infinite dilution have also been calculated. The mixing quantities like (∂V _m^E/∂T)_P and (∂H _m^E/∂P)_T have been calculated at T = 298.15 K and these values are compared with the values calculated from Flory’s theory at equimolar composition.     

Excess enthalpies of some 2-alkanone + 1-chloroalkane binary mixtures at 25 and 35°C

Excess molar enthalpies h^E at 25 and 35° C and atmospheric pressure, are reported for the binary mixtures formed by a 2-butanone and 2-pentanone with 1-chlorobutane, 1-chloropentane, 1-chlorohexane, or 1-chlorooctane. The h^E values for all the mixtures are positive, increasing as the 1-chloroalkane length increases and as the ketone length decreases. Excess molar enthalpies depend slightly on the temperature. The experimental values together with those from the literature were used to calculate the interaction parameters for the Dang-Tassios version of the UNIFAC model.Communicated at the Festsymposium celebrating Dr. Henry V. Kehiaian's 60^th birthday, Clermont-Ferrand, France, 17–18 May 1990.     

Partial molar enthalpies of solution as indicators of interactions in mixtures of 2-butoxyethanol and 2-butanol with water

Calorimetric measurements have been made of differential enthalpies of solution of both components in the binary system 2-butoxyethanol-water and of 2-butanol in the system 2-butanol-water as a function of composition at three different temperatures. The heat capacity changes for dissolution were calculated from the temperature variation of the solution enthalpies. Drastic changes of the solution properties are seen with increasing solute concentration in water-rich solutions. In the 2-butoxyethanol-water system, which could be studied over the whole composition range, four different regions can be identified. At extreme dilution in water, the solute is fully hydrated with a primary hydration layer of monolayer thickness involved in long-range secondary hydration. In dilute solutions the primary hydration layer is unchanged but the secondary hydration diminishes with increasing solute concentration. In semi-dilute solution the primary hydration layer breaks down and the particular hydrophobic characteristics of hydrocarbon groups in aqueous solution disappear. At higher solute content the mixtures show no hydrophobic character but the behavior of regular mixtures of polar solutes.