Die Erniedrigung der Einfriertemperatur organischer Gläser durch Lösungsmittel

Jenckel, Ernst; Heusch, R.

doi:10.1007/bf01519799

Cited by 230 publications

(84 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using the Simha-Boyer rule [67] that establishes that ΔαT g ≈ constant, it results (37) An empirical equation proposed by Jenckel and Heusch [68] expressed in terms of the weight fractions (38) has also been successfully used for different binary mixtures, but it fails when applied to low-molarmass liquids [69] as also observed with eq. 36.…”

Section: Glass Transition Modelsmentioning

confidence: 99%

Empirical and theoretical models of equilibrium and non-equilibrium transition temperatures of supplemented phase diagrams in aqueous systems (IUPAC Technical Report)

Corti

Angell

Auffret

et al. 2010

Pure and Applied Chemistry

View full text Add to dashboard Cite

This paper describes the main thermodynamic concepts related to the construction of supplemented phase (or state) diagrams (SPDs) for aqueous solutions containing vitrifying agents used in the cryo-and dehydro-preservation of natural (foods, seeds, etc.) and synthetic (pharmaceuticals) products. It also reviews the empirical and theoretical equations employed to predict equilibrium transitions (ice freezing, solute solubility) and non-equilibrium transitions (glass transition and the extrapolated freezing curve). The comparison with experimental results is restricted to carbohydrate aqueous solutions, because these are the most widely used cryoprotectant agents. The paper identifies the best standard procedure to determine the glass transition curve over the entire water-content scale, and how to determine the temperature and concentration of the maximally freeze-concentrated solution.

show abstract

Section: Glass Transition Modelsmentioning

confidence: 99%

Empirical and theoretical models of equilibrium and non-equilibrium transition temperatures of supplemented phase diagrams in aqueous systems (IUPAC Technical Report)

Corti

Angell

Auffret

et al. 2010

Pure and Applied Chemistry

View full text Add to dashboard Cite

show abstract

“…Several well-known equations including Gordon-Taylor or modified Fox equation yield reasonable agreement with the experimental date, thanks to the use of at least one empirical fit constant (Jarray et al, 2003). Inasmuch as specific interactions are responsible for the homogeneity of the mixture under consideration here, an alternative equation (Jenckel and Heusch, 1953) offers the advantage to bring some physical meaning. Its expression is:…”

Section: Glass Transition Temperature T Gmentioning

confidence: 63%

Molecular Analysis of the Mechanical Behavior of Plasticized Amorphous Polymer

Boughalmi¹,

Jarray²,

Larbi³

et al. 2006

Oil & Gas Science and Technology - Rev. IFP

View full text Add to dashboard Cite

Résumé -Analyse moléculaire du comportement mécanique de polymères plastifiés -Les effets de la plastification sur le comportement mécanique ont été étudiés sur deux familles de matériaux à base de poly(méthacrylate de méthyle) (PMMA) et de poly(chlorure de vinyle) (PVC). Le PMMA a été mélangé avec du poly(fluorure de vinylidène) (PVDF) dans des proportions massiques en PVDF variant de 0 à 40 %, compositions pour lesquelles ces échantillons sont totalement amorphes. Le di-octylphtalate (DOP) a été mécaniquement dispersé dans le PVC dans des proportions massiques en DOP variant de 0 à 20 %. Le comportement en relaxation des échantillons a été étudié par analyse thermique différentielle avec une rampe de température de 10 °C·min -1 et par analyse dynamique mécanique à une fréquence de 1 Hz sur une plage de température allant de -100 °C jusqu'à 150 °C. Les courbes contrainte -déformation ont été réalisées en compression à une vitesse de déformation de 2.10 -3 s -1 . L'analyse des données a révélé le rôle déterminant des mouvements de relaxation β dans le comportement plastique. En considérant la partie non élastique du travail fourni, une corrélation a été trouvée entre cette quantité et les mouvements de relaxation α et β. Abstract -Molecular Analysis of the Mechanical Behavior of Plasticized Amorphous PolymersPlasticization effects on the mechanical behavior were investigated on two families of materials based on poly(methyl methacrylate) (PMMA) and poly(vinyl chloride) (PVC), respectively. For this purpose, PMMA was blended with poly(vinylidene fluoride) (PVDF) by co-precipitation from solution, all over the

show abstract

“…Jenkel and Heusch (1953) proposed the Equation (6), which accounts for monotonic (all positive or all negative) deviations from the linear combination, where k is an empirical fitting parameter:

T_{g} = w_{1} T_{g 1} + w_{2} T_{g 2} + k w_{1} w_{2}

Kwei (1984) investigated polymer mixtures and proposed the following empirical expression:

T_{g} = \frac{w_{1} T_{g 1} + w_{2} T_{g 2}}{w_{1} + k w_{2}} + q w_{1} w_{2}

…”

Section: Mathematical Models For Prediction Of Glass Transition Tempementioning

confidence: 99%

Section: Mathematical Models For Prediction Of Glass Transition Tempementioning

confidence: 99%

Comparison of mathematical models to predict glass transition temperature of rice (cultivar IRGA 424) measured by dynamic mechanical analysis

Bertotto

Gastón

Batiller

et al. 2018

Food Science & Nutrition

View full text Add to dashboard Cite

Dynamic mechanical analysis (DMA) was applied to measure the Tg of rice IRGA 424 at different moisture content values (9.3%–22.3% wet basis). To conduct temperature sweeps, the samples were heated at a rate of 2°C/min from 20 to 120°C keeping frequency to 1 Hz. Tg was measured both from the E″ peak temperature (Tgmidpoint) and from the tan (δ) peak temperature (Tgendset). Tgmidpoint and Tgendset increased from 31.8 to 86.6°C and 42.1 to 104.7°C, respectively, as moisture content decreased from 22.3 to 9.3%. Six models were tested for their ability to predict Tg as a function of the moisture content. As all residuals were normally distributed and homoskedastic, standard metrics were used to assess the fitted models. Goodness of fit by these models was established by comparing the coefficient of determination (R 2), standard error of the estimate (SEE), and mean relative deviation (MRD). The Gordon–Taylor linearized equation was the most accurate in predicting Tg. To predict Tg from the moisture content of the rice samples, a new expression was proposed. For the conditions considered in this work, the developed equation satisfactorily predicts the Tg of rice IRGA 424 without needing prior linearization.

show abstract

Die Erniedrigung der Einfriertemperatur organischer Gläser durch Lösungsmittel

Cited by 230 publications

References 11 publications

Empirical and theoretical models of equilibrium and non-equilibrium transition temperatures of supplemented phase diagrams in aqueous systems (IUPAC Technical Report)

Empirical and theoretical models of equilibrium and non-equilibrium transition temperatures of supplemented phase diagrams in aqueous systems (IUPAC Technical Report)

Molecular Analysis of the Mechanical Behavior of Plasticized Amorphous Polymer

Comparison of mathematical models to predict glass transition temperature of rice (cultivar IRGA 424) measured by dynamic mechanical analysis

Contact Info

Product

Resources

About