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The solvent uptake in equilibrium of a highly cross-linked epoxy o-cresol novolac resin in water, isopropanol, and heptane was experimentally measured and modeled with the perturbed-chain statistical association fluid theory (PC-SAFT) equation of state. As suggested in the literature, PC-SAFT was combined with a network term, which takes additional elastic forces into account. The model parameters of the epoxy resin were generated by fitting them to the measured solvent uptake in pure substances and to the density of the epoxy resin, which provided a very good agreement with the experimental data. Furthermore, the solvent uptake in the mixtures isopropanol/water and isopropanol/heptane was predicted in very good agreement to the experimental data. For the first time, a thermodynamic model was developed to calculate the solvent uptake in an epoxy resin.

Crystallization from solution is a promising unit operation to separate linear and branched isomers. To reduce the number of experiments, a thermodynamic modeling approach is proposed to calculate the required phase equilibria. Hereby, the thermodynamic data of pure substances are required to fit model parameters, but the branched isomers are often not available. Therefore, a methodology which allows for the prediction of phase equilibria of systems containing branched molecules was developed in this contribution. The basic idea is to fit the model parameters to experimental data of linear molecules and combine these parameters with information about the molecular architecture of the branched isomers to predict the phase equilibria of these isomers. For this purpose the lattice cluster theory which considers directly the molecular architecture was applied in combination with the chemical association lattice model. As model systems linear and branched alkanes dissolved in an alcohol were investigated. The developed methodology is able to predict the binary liquid–liquid equilibria of the branched alkanes dissolved in an alcohol in good agreement to experimental data. Furthermore, the thermodynamic model is able to simultaneously calculate the liquid–liquid equilibrium and the solid–liquid equilibrium with the same model parameters in good agreement with experimental data.

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In this work the interfacial mass transfer of the system water−toluene with four different transferring components (acetone, ethanol, tetrahydrofuran, and acetonitrile) was examined. For this the liquid−liquid equilibria, the interfacial tension, and the mass transfer across the interface of these systems were experimentally determined. On the basis of this experimental data, the theoretical framework, which is based on the Koningsveld−Kleintjens approach and the concentration gradient theory, was parametrized. With the use of the Koningsveld−Kleintjens approach, the liquid− liquid equilibria were modeled and the concentration gradient theory was applied to model the interfacial properties in equilibrium as well as in nonequilibrium. It was shown that the concentration gradient theory in combination with the Koningsveld−Kleintjens approach could be used to model the mass transfer across the interface. Further, a connection between the enrichment of the transferring component at the interface and the time to equilibrate the system was found.