(Liquid+liquid) equilibria of binary polymer solutions using a free-volume UNIQUAC-NRF model

Radfarnia, Hamid R.; Ghotbi, Cyrus; Taghikhani, Vahid; Kontogeorgis, Georgios M.

doi:10.1016/j.jct.2005.10.005

Cited by 8 publications

(10 citation statements)

References 17 publications

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“…The interpretation of the LCST is more difficult, but it is generally accepted that it occurs when an unfavourable entropy effect is present, that is, when negative entropy of mixing overcomes the negative enthalpies of mixing. The LCST is associated with large differences in thermal expansion of solvent and solute or in free-volume percentage as it occurs between polymer and solvent mixtures [1]. Thus, in general the presence of UCST is the most frequent case for binary mixtures of small (non-polymeric) molecules.…”

Section: Introductionmentioning

confidence: 99%

“…Some discussion on this matter regarding other models has been published. For example, Radfarnia et al [1] established that the most widely used lattice model for polymer solutions, the Flory-Huggins theory [12], cannot describe the lower critical solution temperature (LCST) behaviour. Many other papers have been dedicated to the experimental measurement and correlation of LLE data for polymer solutions.…”

Section: Introductionmentioning

confidence: 99%

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Liquid–Liquid Equilibrium Data Correlation Using NRTL Model for Different Types of Binary Systems: Upper Critical Solution Temperature, Lower Critical Solution Temperature, and Closed Miscibility Loops

Olaya

Carbonell-Hermida

Trives

2020

Ind. Eng. Chem. Res.

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In this work, LLE data at different temperatures have been correlated for 30 binary systems that presented different miscibility behaviour: 15 upper critical solution temperature (UCST), 5 critical solution temperature (LCST) and 10 closed loop LLE region systems. The NRTL model along with an expression frequently used in literature for the temperature dependence in the binary interaction has allowed an acceptable fitting of all the systems. The parameters obtained have been validated by both the inspection of the Gibbs energy of mixing function regarding the fulfilment of the Gibbs common tangent equilibrium condition, and also the stability of the solution to avoid possible metastable equilibrium solutions. The critical solution temperatures have been calculated by extrapolation using the NRTL parameters obtained for all selected binary systems.Moreover, the NRTL parameter values have been analysed using some proposed representations that also include the boundary curve between miscible (L) and partially miscible (LLE) regions. These graphical representations are useful because they show the parameter value requirements to reproduce UCST, LCST or closed loop behaviours.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Liquid–Liquid Equilibrium Data Correlation Using NRTL Model for Different Types of Binary Systems: Upper Critical Solution Temperature, Lower Critical Solution Temperature, and Closed Miscibility Loops

Olaya

Carbonell-Hermida

Trives

2020

Ind. Eng. Chem. Res.

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“…The polymer solution can reveal the upper or lower critical solution temperatures (UCST) or (LCST) in the mixtures with water, alcohol, ketone, or aliphatic hydrocarbons [15][16][17]. The HPs are new compounds and there is a lack of accurate phase equilibria and thermodynamic experimental data for these polymers.…”

Section: Introductionmentioning

confidence: 99%

Solubility of hyperbranched polymer, Boltorn W-3000, in alcohols, ethers and hydrocarbons

Domańska¹,

Żołek‐Tryznowska²

2010

The Journal of Chemical Thermodynamics

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“…7 Radfarnia et al studied VLE and LLE phase behavior of polymer solutions using modified quasi-chemical model and the UNIQUAC-NRF-FV model. 8,9 In this research, the model proposed by Pazuki et al to study the phase behavior of amino acids and simple peptides in aqueous solutions 10 has been extended for polymer solutions, Gibbs free energy of polymer solution, and activity coefficients of polymer and solvent. Vapor-liquid equilibrium of polymer solutions has been correlated using the proposed model and the results have been compared with those of the UNIQUAC-FV model.…”

Section: Introductionmentioning

confidence: 99%

Study of VLE phase behavior and correlating the thermophysical properties of polymer solutions using a local composition‐based model

Pazuki

Taghikhani

Vossoughi

2009

J of Applied Polymer Sci

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In this study, the recently proposed model by Pazuki et al., based on the local composition concept (LCC), has been used in correlating the vapor-liquid phase behavior of polymer solutions. Similar to the LCC models available in the literature, the proposed model has two combinatorial and residual terms to account for both entropic as well as enthalpic effects in solution. The Flory-Huggins model has been considered as the combinatorial part of the proposed model, while the equation proposed by Pazuki et al. was considered as the residual term. The proposed model has been used in correlating the vapor-liquid phase behavior for a large number of polymer-solvent mixtures at different conditions. The results obtained from the proposed model have been compared with those obtained from the UNIQUAC-FV model. The results showed that the proposed model can accurately correlate the VLE data for polymer solutions studied in this work. Also, the proposed model has been used to obtain the thermophysical properties such as density, viscosity, and excess enthalpy for these polymer solutions. The results in connection with the thermophysical properties obtained from the proposed model have been compared with those obtained from the Poly-NRTL and the Poly-Wilson models. The results showed that the proposed model can accurately correlate the properties of polymer solutions at various conditions.

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(Liquid+liquid) equilibria of binary polymer solutions using a free-volume UNIQUAC-NRF model

Cited by 8 publications

References 17 publications

Liquid–Liquid Equilibrium Data Correlation Using NRTL Model for Different Types of Binary Systems: Upper Critical Solution Temperature, Lower Critical Solution Temperature, and Closed Miscibility Loops

Liquid–Liquid Equilibrium Data Correlation Using NRTL Model for Different Types of Binary Systems: Upper Critical Solution Temperature, Lower Critical Solution Temperature, and Closed Miscibility Loops

Solubility of hyperbranched polymer, Boltorn W-3000, in alcohols, ethers and hydrocarbons

Study of VLE phase behavior and correlating the thermophysical properties of polymer solutions using a local composition‐based model

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