Naslov
The segmental interaction model for liquid-liquid equilibria correlation and prediction. Application to polymer-solvent systems

Autori
Bogdanić, Grozdana ; Vidal, Jean

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
17th European Seminar on Applied Thermodynamics,Book of Abstracts / Macedo Almeida, M. E. R. - Porto : University of Porto, 1999

Skup
17th European Seminar on Applied Thermodynamics

Mjesto i datum
Vilamoura, Portugal, 13.05.1999. - 16.05.1999

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
LLE; correlation; prediction; segmental interaction model; polymer-solvent systems

Sažetak
The segmental interaction model containing the combinatorial, free-volume and energetic contributions to the excess Gibbs energy for correlation/prediction of liquid-liquid equilibria (LEE) of polymer solutions has been developed1,2. The energetic contribution is based on the solution of segment concept. The groups are defined as the polymer or copolymer segments (repeating units) or solvent molecules, as is usually done when applying the mean field theory3. Group activity coefficients are calculated through the UNIQUAC model. The informations used to determine the parameters include the experimental LLE data, the densities of the solvent and the polymer at the temperature of the mixture, the van der Waals volumes for the calculation of the free volume-combinatorial contribution, and the molecular surface parameters of the segments for the application of the UNIQUAC model. The densities are estimated using the DIPPR data bank4 for the solvent and the Polymer Solution Handbook5 for the Tait equation parameters. The van der Waals volumes and molecular surface parameters are calculated through additive group contributions6,7. Previous application of the model was related to the LLE correlation/prediction of nonpolar and moderately polar systems and the present work shows that the extension to a system with strong specific interactions is possible. The lower and upper critical solution temperatures as well as the closed loop diagrams for numerous systems are correlated/predicted, using weakly temperature dependent UNIQUAC parameters. The main limitation is probably the immediate proximity of the critical point of the solvent, where the excess volume of the solution cannot be described. ________________________________ 1. G.Bogdanić, J.Vidal, 16th European Seminar on Applied Thermodynamics, Abbaye des Premontres, Pont-a-Mousson, France, 19th-22th June 1997, Proceedings, p.73. 2. E.Panagou, J.Vidal, G.Bogdanić, Polym.Bull., 40,117-123(1998). 3. G. ten Brinke, F.E. Karasz, W.J. MacKnight, Macromolecules, 16,1827-1832(1983). 4. T.E.Daubert, R.P.Danner, Data Compilation Tables of Properties of Pure Compounds, Design Institute for Physical Property Data, AIChE, 1985. 5. R.P.Danner, M.S.High, Polymer Solution Handbook, AIChE, Pennsylvania State University, 1992. 6. Aa.Fredenslund, J.Gmehling, P.Rasmussen, Vapor-Liquid Equilibria Using UNIFAC, Elsevier Scientific, New York, 1997. 7. A.Bondi, Physical Properties of Molecular Crystals, Liquid and Glasses, Wiley, New York, 1968.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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