The Chemical Thermodynamic Models for Calculating the Solvent Activity Coefficient of Semidiluted Aqueous and Nonaqueous Polymer Solutions in Vapor–Liquid Equilibrium

Sadeghi, Rahmat; Shahebrahimi, Yasaman; Zonnouri, Ashkan

doi:10.1021/acs.jced.5b00362

Cited by 5 publications

(3 citation statements)

References 29 publications

(65 reference statements)

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“…When the experimental data are not accessible, it is necessary to have more accurate tools to predict the thermophysical properties. Different approaches, such as temperature and composition dependence of viscosity models, activity models, , and equations of state, can be taken into account to model the thermophysical behavior. The corresponding predicted and correlated equations are dependent on numerous constant and adjustable parameters.…”

Section: Introductionmentioning

confidence: 99%

Densities, Viscosities, Refractive Indices, and Excess Properties of Aqueous 1,2-Etanediol, 1,3-Propanediol, 1,4-Butanediol, and 1,5-Pentanediol Binary Mixtures

Moosavi

Rostami

2016

J. Chem. Eng. Data

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The thermodynamic and transport properties of aqueous alkanediol systems at atmospheric pressure were studied over the whole concentration range using the experimental values of density and refractive index at temperatures of 288.15−318.15 K with 5 K interval and viscosity at T = 293.15, 298.15, and 303.15 K. The obtained data were compared with those available in literature. A detailed analysis regarding the behavior of aqueous alkanediols and interactions between the mixture components was performed using different excess thermodynamic properties. Moreover, McAllister model and Grunberg−Nissan and its new proposed models were applied to predict the viscosity data. The validity of the proposed equations was assessed by comparisons between the experimental values and those obtained by the models.

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Section: Introductionmentioning

confidence: 99%

Densities, Viscosities, Refractive Indices, and Excess Properties of Aqueous 1,2-Etanediol, 1,3-Propanediol, 1,4-Butanediol, and 1,5-Pentanediol Binary Mixtures

Moosavi

Rostami

2016

J. Chem. Eng. Data

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“…Other research groups have used VLE data to obtain correlations for the activity coefficients of water and caprolactam in molten nylon over a range of operating conditions (i.e., using NRTL, Flory‐Huggins, UNIFAC, PCSAFT approaches) . However, aside from the work of Steppan et al.…”

Section: Reaction Mechanism and Literature Reviewmentioning

confidence: 99%

Modeling Equilibrium Behavior of Nylon 6, Nylon 6,6 and Nylon 6/6,6 Copolymer

Liu

Marchildon

McAuley

2019

Macro Reaction Engineering

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Nylon 6 and nylon 6,6 reaction equilibria depend in a complex way on water concentration and temperature. For example, data sets from six research groups reveal that the apparent equilibrium constant for polycondensation increases with water at low water concentrations, reaches a maximum, and then decreases as the water concentration rises further. In this article, semi‐empirical expressions are proposed to describe the experimentally observed equilibrium behavior for the five main reactions that occur during nylon 6 and nylon 6,6 polymerization. Nine side reactions involving amidine ends, cyclopentanone ends, and hydrated carboxyl ends are used to develop expressions that account for the influence of both water and temperature on these equilibrium constants. Excellent fit to the data, over the entire range of the available nylon 6 and nylon 6,6 literature data, suggests that the proposed equations will be helpful for modeling reaction equilibria for nylon 6/6,6 copolymerization.

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“…The appropriate models provide the development of a quantitative description of the experimental data and can predict the phase behavior of simple and complex solutions. − However, there is not a universally valid model to forecast the phase behavior of biological solutions. Several empirical equations for the solvent activity coefficient in the binary aqueous urea solutions have been proposed in the literature. ,, Recently, Sadeghi et al used the PC-SAFT equation of state for the modeling of mean ionic activity coefficients and osmotic coefficients at 300.15 K in aqueous electrolyte solutions containing urea of different concentrations …”

Section: Introductionmentioning

confidence: 99%

Vapor–Liquid Equilibrium of Aqueous Urea Solution from Dynamic Vapor Sorption Measurements at 283.15–343.15 K

Shahebrahimi

Fazlali

2020

J. Chem. Eng. Data

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Urea solution as a biopolymer denaturing agent and source of nitrogen fertilizer has a key role in some industries, and it seems necessary to study the phase behavior of this system. This work aims to investigate the vapor–liquid equilibria (VLE) of aqueous urea solutions over a wide range of concentrations and temperatures. For this purpose, water activity measurements were performed for the aqueous urea solution using the dynamic vapor sorption (DVS) technique at 283.15–343.15 K in the various urea concentrations. The results showed good agreement between obtained data using DVS and the isopiestic technique at 298.15 K. The conductivity value of the urea solution at 298.15 K revealed that this system is a very weak electrolyte solution. Thereby, a combination of Pitzer’s extension of the Debye–Huckel function (PDH) to cover the ion interaction and some local composition models including Wilson, nonrandom two-liquid (NRTL), nonrandom factor (NRF), modified Wilson-NRF, and NRTL-NRF to point to physical interaction was considered to correlate the experimental activity data. It was revealed that increasing the temperature led to increasing the accuracy of NRTL-NRF and NRF models and other models can correlate the experimental data at any temperature in this range well.

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The Chemical Thermodynamic Models for Calculating the Solvent Activity Coefficient of Semidiluted Aqueous and Nonaqueous Polymer Solutions in Vapor–Liquid Equilibrium

Cited by 5 publications

References 29 publications

Densities, Viscosities, Refractive Indices, and Excess Properties of Aqueous 1,2-Etanediol, 1,3-Propanediol, 1,4-Butanediol, and 1,5-Pentanediol Binary Mixtures

Densities, Viscosities, Refractive Indices, and Excess Properties of Aqueous 1,2-Etanediol, 1,3-Propanediol, 1,4-Butanediol, and 1,5-Pentanediol Binary Mixtures

Modeling Equilibrium Behavior of Nylon 6, Nylon 6,6 and Nylon 6/6,6 Copolymer

Vapor–Liquid Equilibrium of Aqueous Urea Solution from Dynamic Vapor Sorption Measurements at 283.15–343.15 K

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