UNIFAC-FV Applied to Dendritic Macromolecules in Solution:  Comment on “Vapor−Liquid Equilibria for Dendritic-Polymer Solutions” (Lieu, J. G.; Liu, M.; Fréchet, J. M. J.; Prausnitz, J. M. J. Chem. Eng. Data 1999, 44, 613−620)

Tande, Brian M.; Deitcher, Robert W.; Sandler, and Stanley I.; Wagner, Norman J.

doi:10.1021/je015505z

Cited by 7 publications

(4 citation statements)

References 17 publications

(20 reference statements)

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“…A typical problem in polymer processing involves the determination of thermodynamic properties of mixtures of polymers, solvents, plasticizers, antiplasticizers, and diluents. Predictive thermodynamic models for describing phase equilibria of polymer−solvent systems can be classified into two general categories: activity coefficient models (e.g., UNIFAC-FV, − entropic-FV, , FH/Hansen, GK-FV 249 and UNIFAC-ZM − ) and equations of state (e.g., PSRK, GC-Flory EOS − and GCLF EOS − ). Equations of state are preferred over activity coefficient models in that equations of state can disclose the dependence of phase volume on pressure, which is especially important in estimating the swelling degree of polymers in polymer processing.…”

Section: Solvent−polymer Systemsmentioning

confidence: 99%

Predictive Molecular Thermodynamic Models for Liquid Solvents, Solid Salts, Polymers, and Ionic Liquids

et al. 2008

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solubility, swelling degree, and crystallinity of polymers in polymer processing.Undoubtedly, predictive molecular thermodynamic models are very important in separation processes and polymer processing. In the separation processes (e.g., extractive distillation, liquid-liquid extraction, absorption, etc.), a third solvent is commonly needed to add into the components to be separated so as to improve the separation factor. 1,2 So the solvent (entrainer or separating agent) is the core, and a suitable solvent plays an important role in the economical design of separation processes. However, it is tiresome to choose the best solvent from thousands of different substances for a given system through experiments. We should identify the relation between molecular structure of the solvent and separation performance. In this case, predictive molecular thermodynamic models are used as a screening tool to find out the best suited solvent rapidly. Only on this

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Section: Solvent−polymer Systemsmentioning

confidence: 99%

Predictive Molecular Thermodynamic Models for Liquid Solvents, Solid Salts, Polymers, and Ionic Liquids

et al. 2008

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“…1. In the papers of Lieu et al and Tande et al, all dendrimers were assumed to have a density of 1 g/cm 3 . The influence of this rather simplified assumption in the performance of the models is evaluated.…”

Section: Database and Resultsmentioning

confidence: 99%

Free-Volume Activity Coefficient Models for Dendrimer Solutions

Giesen

Michelsen

Kontogeorgis

2002

Ind. Eng. Chem. Res.

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The ability of the Unifac-FV and Entropic-FV models to predict phase equilibria for dendrimer systems is investigated in this work. Different approaches are considered for the estimation of the density of the dendrimers, which is required as input parameter in the free-volume models. The density is not always available for such polymers.The predictions obtained by the two models are compared with recent vapor-liquid equilibrium experimental data for dendrimer systems. It is shown in this study that both methods represent satisfactorily the experimental data in many cases, whereas Unifac-FV performs better for PAMAM dendrimers (where some of the interaction parameters are missing). However, Unifac-FV is the model that is most influenced by the dendrimer's density. Both models yield better results when experimental densities are employed (for AR dendrimers), but in those cases where such data are not available, predicted densities can be reliably obtained via the van Krevelen method (for C12 and A4 dendrimers).

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“…The UNIFAC-FV model was already proven to be of value for the representation of vapor−liquid equilibria of dendritic polymer solutions. ,− In modeling phase equilibria in systems with dendritic polymers, it is important to take into account the structure and the large number of functional end groups of these polymers. Both peculiarities of the macromolecules show dominating effects on the phase behavior but are not explicitly included in many modeling approaches.…”

Section: Primary Data Reduction and Modelingmentioning

confidence: 99%

“…Since OH-terminated hyperbranched polymers exhibit comparatively large hydrodynamic radii in good polar solvents, allowing for the penetration of the solvent molecules into the interior of the hyperbranched polymers, it was assumed that all polymeric structure groups (dendritic, linear, and terminal groups) contribute to the residual activity . Tande et al manipulated the b parameter in the free volume part of the activity with regard to the penetrability of the solvent into the hyperbranched polymer molecule …”

Section: Primary Data Reduction and Modelingmentioning

confidence: 99%

Potential of Branched Polymers in the Field of Gas Absorption: Experimental Gas Solubilities and Modeling

Rolker

Seiler

Mokrushina

et al. 2007

Ind. Eng. Chem. Res.

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In this work, the potential of low-viscous branched polymers for gas separation applications such as CO 2 absorption from flue gas is examined. Carbon dioxide and nitrogen solubilities are measured at low pressures for linear and branched polyethers, hyperbranched polyesters, and polyamines such as a polyamidoamine and a polyethylene imine as well as in their aqueous solutions. The results are reported in terms of Henry constants in the temperature range T ) 310-370 K. The densities of the pure polymers and their aqueous solutions are measured between T ) 293.15 and 363.15 K. The selectivities of the polymers for CO 2 /N 2 and the enthalpies of absorption at infinite dilution are determined. The group-contribution method UNIFAC-FV is applied to the CO 2 solubilities in polyethers and the hyperbranched polyester. It has been shown that branched polymers are promising candidates for gas absorbents with a high capacity for CO 2 and with large selectivities. The UNIFAC-FV model is able to predict the CO 2 solubilities in the investigated polymers.

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UNIFAC-FV Applied to Dendritic Macromolecules in Solution: Comment on “Vapor−Liquid Equilibria for Dendritic-Polymer Solutions” (Lieu, J. G.; Liu, M.; Fréchet, J. M. J.; Prausnitz, J. M. J. Chem. Eng. Data 1999, 44, 613−620)

Cited by 7 publications

References 17 publications

Predictive Molecular Thermodynamic Models for Liquid Solvents, Solid Salts, Polymers, and Ionic Liquids

Predictive Molecular Thermodynamic Models for Liquid Solvents, Solid Salts, Polymers, and Ionic Liquids

Free-Volume Activity Coefficient Models for Dendrimer Solutions

Potential of Branched Polymers in the Field of Gas Absorption: Experimental Gas Solubilities and Modeling

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