Chemical Engineering / Kimya Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/14

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  • Article
    Citation - WoS: 13
    Citation - Scopus: 15
    Determination of Thermodynamic and Transport Properties of Solvents and Non Solvents in Poly(l-Lactide
    (John Wiley and Sons Inc., 2006) Eser, Hülya; Tıhmınlıoğlu, Funda
    Thermodynamic properties, partition coefficient, and diffusion coefficients of the various solvents (acetone, dichloromethane, trichloromethane, ethyl acetate, ethyl alcohol, tetrahydrofuran, and water) in poly(lactide-co- glycolide) (PLGA) at infinite dilution of the solvent have been determined by inverse gas chromatography (IGC). In IGC method, which is based on the characteristic equilibrium partitioning of a solute between a mobile phase and a stationary phase, a small pulse of solvent is introduced into the column and by the aid of retention volume of the solvent, several polymer solvent interaction properties, namely retention volume (Vg), infinitely dilute weight fraction activity coefficient (Ω1∞), Flory-Huggins interaction parameter (χ), and solubility parameters of the polymer (δ2∞) can be determined. The thermodynamic results indi cated that trichloromethane and dichloromethane were the most suitable solvents among all the solvents studied for PLGA. The partition (K) and diffusion coefficients (Dp) of various solvents at infinite dilution of the solvent were calculated by using the model developed by Pawlisch et al. (Macromolecules 1987, 20, 1564). The optimum K and D p values that best fit the data were found and the model predicted experimental data very well. So IGC method is a powerful tool for the determination of thermodynamic and diffusion properties of solvent in polymer at infinite dilution of the solvent.
  • Article
    Citation - WoS: 18
    Citation - Scopus: 22
    Application of Inverse Gas Chromatography To the Measurement of Diffusion and Phase Equilibria in Polyacrylate-Solvent Systems
    (Elsevier Ltd., 1999) Tıhmınlıoğlu, Funda; Danner, Ronald P.
    The inverse gas chromatography technique (IGC) was used to determine the partition and diffusion coefficients of ethyl acetate and 2-ethylhexyl acrylate in polyacrylate for both infinite dilution and finite concentrations of solvent. Experiments were performed over a temperature range of 60 to 100°C, more than 100°C above the glass transition temperature of the polymer. The capillary column IGC model previously developed for determining partition and diffusion coefficients of infinitely dilute solvent has been modified to account for the concentration of the solvent in the polymer phase. Thermodynamic data obtained from retention theory and the modified capillary column IGC model are compared