### Abstract

In this work the density gradient theory in combination with different Gibbs excess energy (G^{E}) models is used to model the demixing behavior of binary polymer mixtures. The investigated polymer mixtures are Polydimethylsiloxane/Polytetramethyldisiloxanylethylene, Phenylethylether/Polydimethylsiloxane and Boltorn U3000/propanol. As G^{E}-models, the Koningsveld-Kleintjens model and the Lattice Cluster Theory combined with the extended chemical association lattice model were used. So we could show that the density gradient theory combined with different G^{E}-models to consider molecular influences, as association or molecular architecture, can model the demixing of polymer mixtures. The influence parameter required by the density gradient theory was fitted to experimental interfacial tension data. We have shown that the density gradient theory allows modeling the experimentally observed phenomena known from phase equilibria measurements as longer demixing times near the spinodal curve and for shorter tie lines. Moreover, the density gradient theory predicts a change in the interfacial composition near the equilibrium. But this composition change cannot be considered by common sharp interface models assuming a stable interface during the whole separation process.

Original language | English |
---|---|

Pages (from-to) | 42-49 |

Number of pages | 8 |

Journal | Journal of Molecular Liquids |

Volume | 209 |

DOIs | |

Publication status | Published - 28 May 2015 |

### Fingerprint

### Keywords

- Cahn-Hilliard
- Density gradient theory
- Extended chemical association lattice model
- Interfacial properties
- Koningsveld-Kleintjens
- Lattice Cluster Theory
- Liquid-liquid demixing

### ASJC Scopus subject areas

- Physical and Theoretical Chemistry
- Spectroscopy
- Condensed Matter Physics
- Atomic and Molecular Physics, and Optics
- Electronic, Optical and Magnetic Materials
- Materials Chemistry

### Cite this

*Journal of Molecular Liquids*,

*209*, 42-49. https://doi.org/10.1016/j.molliq.2015.05.012

**Demixing behavior of binary polymer mixtures.** / Kulaguin Chicaroux, Andres; Górak, Andrzej; Zeiner, Tim.

Research output: Contribution to journal › Article › Research › peer-review

*Journal of Molecular Liquids*, vol. 209, pp. 42-49. https://doi.org/10.1016/j.molliq.2015.05.012

}

TY - JOUR

T1 - Demixing behavior of binary polymer mixtures

AU - Kulaguin Chicaroux, Andres

AU - Górak, Andrzej

AU - Zeiner, Tim

PY - 2015/5/28

Y1 - 2015/5/28

N2 - In this work the density gradient theory in combination with different Gibbs excess energy (GE) models is used to model the demixing behavior of binary polymer mixtures. The investigated polymer mixtures are Polydimethylsiloxane/Polytetramethyldisiloxanylethylene, Phenylethylether/Polydimethylsiloxane and Boltorn U3000/propanol. As GE-models, the Koningsveld-Kleintjens model and the Lattice Cluster Theory combined with the extended chemical association lattice model were used. So we could show that the density gradient theory combined with different GE-models to consider molecular influences, as association or molecular architecture, can model the demixing of polymer mixtures. The influence parameter required by the density gradient theory was fitted to experimental interfacial tension data. We have shown that the density gradient theory allows modeling the experimentally observed phenomena known from phase equilibria measurements as longer demixing times near the spinodal curve and for shorter tie lines. Moreover, the density gradient theory predicts a change in the interfacial composition near the equilibrium. But this composition change cannot be considered by common sharp interface models assuming a stable interface during the whole separation process.

AB - In this work the density gradient theory in combination with different Gibbs excess energy (GE) models is used to model the demixing behavior of binary polymer mixtures. The investigated polymer mixtures are Polydimethylsiloxane/Polytetramethyldisiloxanylethylene, Phenylethylether/Polydimethylsiloxane and Boltorn U3000/propanol. As GE-models, the Koningsveld-Kleintjens model and the Lattice Cluster Theory combined with the extended chemical association lattice model were used. So we could show that the density gradient theory combined with different GE-models to consider molecular influences, as association or molecular architecture, can model the demixing of polymer mixtures. The influence parameter required by the density gradient theory was fitted to experimental interfacial tension data. We have shown that the density gradient theory allows modeling the experimentally observed phenomena known from phase equilibria measurements as longer demixing times near the spinodal curve and for shorter tie lines. Moreover, the density gradient theory predicts a change in the interfacial composition near the equilibrium. But this composition change cannot be considered by common sharp interface models assuming a stable interface during the whole separation process.

KW - Cahn-Hilliard

KW - Density gradient theory

KW - Extended chemical association lattice model

KW - Interfacial properties

KW - Koningsveld-Kleintjens

KW - Lattice Cluster Theory

KW - Liquid-liquid demixing

UR - http://www.scopus.com/inward/record.url?scp=84930226443&partnerID=8YFLogxK

U2 - 10.1016/j.molliq.2015.05.012

DO - 10.1016/j.molliq.2015.05.012

M3 - Article

VL - 209

SP - 42

EP - 49

JO - Journal of Molecular Liquids

JF - Journal of Molecular Liquids

SN - 0167-7322

ER -