Diffusion coefficients in systems LDPE+cyclohexane and LDPE+benzene

Randová, Alena; Bartovská, Lidmila; Hovorka, Štěpán; Bartovský, Tomáš; Izák, Pavel; Poloncarzová, Magda; Fries, Karel

doi:10.1515/epoly.2010.10.1.742

Cited by 2 publications

(2 citation statements)

References 17 publications

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“…To fully elucidate the extractables migration processes from LDPE to hexane and lipid, it is necessary to consider the impact of LDPE-lipid and LDPE-hexane interactions, as indicated by the solvent absorption or swelling data [33,83]. Table 4 shows the results of collection of LDPE by lipids, oils, oils and organic solvents [40,47,[84][85][86][87][88][89][90][91][92][93][94].…”

Section: Collection Of Solvent Absorption and Swelling Data For Ldpementioning

confidence: 99%

Evaluation of Thermodynamic and Kinetic Contributions to Over-Extraction of Extractables by Nonpolar Organic Solvents in Comparison to Lipids in Exhaustive and Exaggerated Extractions of Medical Devices Based on Abraham Solvation Model and Solvent–Material Interactions Using Low-Density Polyethylene as a Representative Material

2024

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The thermodynamic and kinetic contributions to the over-extraction of extractables by nonpolar organic solvents relative to biological lipids in exhaustive and exaggerated extractions of medical devices are studied based on the Abraham solvation model and solvent–material interactions, using low-density polyethylene (LDPE) as an exemplary material. The thermodynamic effect is evaluated by the partition constant of extractables between LDPE and extraction solvents, hexane and lipids, defined as the concentration in the polymer phase divided by the concentration in the solvent phase. The Abraham solvation model is used to correlate the measured LDPE-lipid partition constant (log10Pldpe/lipid) to construct the predictive model. Similar models are also derived from the thermodynamic cycle conversion, using the system constants of LDPE-water and Lipid-water partition systems. These constructed models, together with the predictive LDPE-hexane (log10Pldpe/hexane) model established from a previous study, are used to predict and compare the ranges and values of Pldpe/s (s = lipids and hexane) for the observed LDPE extractables over a wide hydrophobicity range in log10Po/w from zero to 30. The solvent-LDPE interactions are examined by the degree of swelling of LDPE by hexane (or other nonpolar solvents) and lipids, including the solvent diffusion rates into the material. These parameters allow the evaluation of kinetic effect on the over-extraction. The extent of over-extraction is compiled directly by experimental “overall” or “specific” migration data or indirectly calculated by the diffusion coefficient of extractables when extracted by hexane or lipids. It is concluded from this study that the extractables distribution between LDPE and lipids highly favors the lipid phase thermodynamically (Pldpe/lipid<1), and the values of Pldpe/lipid are always lower than those of Pldpe/hexane, thereby indicating that the thermodynamic effect is not the cause of over-extraction. It is the kinetic effect that dominantly contributes to the over-extraction, as supported by the material swelling and solvent diffusion rates. Finally, the extent of over-extraction has been established from a few folds to over a hundred-fold, and the median value is 7. Furthermore, the methods adopted and developed in this study can be invaluable tools in other disciplines such as the reliable prediction of extractables from other device materials and environmental sampling.

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Section: Collection Of Solvent Absorption and Swelling Data For Ldpementioning

confidence: 99%

Evaluation of Thermodynamic and Kinetic Contributions to Over-Extraction of Extractables by Nonpolar Organic Solvents in Comparison to Lipids in Exhaustive and Exaggerated Extractions of Medical Devices Based on Abraham Solvation Model and Solvent–Material Interactions Using Low-Density Polyethylene as a Representative Material

2024

Liquids

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“…One type of chemical engineering process, where mixed solvents have found broad use is separation of components from mixtures. Our research is focused on membrane separation processes and, as a further challenge, on the separation of single enantiomers from their racemic mixtures. The preparation of single enantiomers is important in the pharmaceutical industry and in pharmacology because two enantiomers may exhibit completely different biological or pharmacological activities, pharmacokinetic profiles or effectiveness, or they may exhibit different potency, as the interacting molecules in biological systems are also chiral .…”

Section: Introductionmentioning

confidence: 99%

Describing the sorption characteristics of a ternary system of benzene (1) and alcohol (2) in a nonporous polymer membrane (3) by theFlory–Huggins model

Hovorka

Randová

Sysel

et al. 2014

Polymer Engineering & Sci

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The Flory-Huggins equation was used to describe results of total and preferential sorption measurements for the binary liquid mixture of benzene (1) and alcohol (2) in one of two nonporous polymer membranes (3), low-density polyethylene (LDPE) and Nafion membrane. The concentration dependence of binary and ternary interaction parameters was determined. The interaction parameters for the benzene -methanol binary mixture were obtained from binary vapor-liquid equilibrium data in the literature to decrease the number of adjusted parameters. The results show that use of a ternary interaction parameter is necessary. Data treatment was performed assuming either no crystallinity or an average crystallinity typical for the studied membranes. Subsequently, the limiting activity coefficients of solutes in LDPE were calculated from the values of the interaction parameters and their values compared to values of the limiting activity coefficients of benzene and methanol in hypothetical liquid alkane with the same density as LDPE obtained by the UNIFAC method. POLYM. ENG. SCI., 55:1187-1195

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Diffusion coefficients in systems LDPE+cyclohexane and LDPE+benzene

Cited by 2 publications

References 17 publications

Describing the sorption characteristics of a ternary system of benzene (1) and alcohol (2) in a nonporous polymer membrane (3) by theFlory–Huggins model

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