Relation for Solid−Liquid Coexistence Systems and Its Application to Melting Point Depression of Benzene in Natural Rubber

1999 ◽  
Vol 103 (25) ◽  
pp. 5353-5360 ◽  
Author(s):  
Yoshio Hoei ◽  
Yoshiyuki Ikeda ◽  
Muneo Sasaki
Keyword(s):  
Melting Point ◽  
Natural Rubber ◽  
Melting Point Depression ◽  
Solid Liquid

Determining solid/liquid interfacial energies in Al-Cu by curvature controlled melting point depression

2018 ◽  
Vol 147 ◽  
pp. 113-121 ◽  
Author(s):  
S. Lippmann ◽  
C. Simon ◽  
S. Zechel ◽  
M. Seyring ◽  
U.S. Schubert ◽  
...  
Keyword(s):  
Melting Point ◽  
Melting Point Depression ◽  
Interfacial Energies ◽  
Solid Liquid

Analysis of Melting Point Depression of Benzene in Crosslinked Natural Rubber by a Frozen Tube Network Model

2005 ◽  
Vol 78 (5) ◽  
pp. 827-843 ◽  
Author(s):  
Y. Hoei
Keyword(s):  
Free Energy ◽  
Melting Point ◽  
Natural Rubber ◽  
Network Model ◽  
Melting Point Depression ◽  
Tube Model ◽  
Melting Thermodynamics

Abstract Literature reports from studies by Jackson and McKenna show a large difference in melting point depression between highly and lightly crosslinked (concentrated) natural rubber/benzene samples. Here, an equation for a tube model is developed to describe particularly the highly crosslinked mixtures at both swelling-and-melting equilibrium. On the basis of Flory-Huggins and Gibbs-Thomson equations, the model involves a swelling-and-melting thermodynamics that includes an elastic contribution to a free energy for a “real chain” network swollen in a good solvent. The freezing of the good solvent, then, occurs within the network chains which act as a confining (frozen) hard tube (having an unfrozen good solvent within). Consequently, the model can explain reasonably well the melting point depression of the highly crosslinked samples in the comparison of their estimates for crystallite (frozen tube) dimensions with certain corresponding literature values.

scholarly journals Activity modelling of the solid–liquid equilibrium of deep eutectic solvents

2019 ◽  
Vol 91 (8) ◽  
pp. 1341-1349 ◽  
Author(s):  
Laura J.B.M. Kollau ◽  
Mark Vis ◽  
Adriaan van den Bruinhorst ◽  
Gijsbertus de With ◽  
Remco Tuinier
Keyword(s):  
Melting Point ◽  
Binary Mixtures ◽  
Order Term ◽  
Deep Eutectic Solvents ◽  
Melting Point Depression ◽  
Ideal Behavior ◽  
Liquid Phase Boundary ◽  
Melting Temperatures ◽  
Sustainable Solvents ◽  
Solid Liquid

Abstract Compared to conventional solvents used in the chemical industry, deep eutectic solvents (DESs) are considered as promising potentially sustainable solvents. DESs are binary mixtures and the resulting liquid mixture is characterized by a large melting point depression with respect to the melting temperatures of its constituents. The relative melting point depression becomes larger as the two components have stronger attractive interactions, resulting in non-ideal behavior. The compositional range over which such binary mixtures are liquids is set by the location of the solid–liquid phase boundary. Here we present experimental phase diagrams of various recent and new DESs that vary in the degree of non-ideality. We investigate whether thermodynamic models are able to describe the solid–liquid equilibria and focus on relating the parameters of these models to the non-ideal behavior, including asymmetric behavior of the activity coefficients. It is shown that the orthogonal Redlich–Kister-like polynomial (OP) expansion, including an additional first order term, provides an accurate description. This theory can be considered as an extension of regular solution theory and enables physical interpretation of the fit parameters.

Melting and Crystallization of Poly(oxyethylene) Mixtures

1995 ◽  
Vol 60 (11) ◽  
pp. 1855-1868 ◽  
Author(s):  
Ivo Lapeš ◽  
Josef Baldrian ◽  
Ján Biroš ◽  
Julius Pouchlý ◽  
Hanes Mio
Keyword(s):  
Melting Point ◽  
Lamellar Structure ◽  
Composition Dependence ◽  
Eutectic Phase ◽  
Eutectic Melting ◽  
Pure Polymer ◽  
X Ray ◽  
Long Period ◽  
Solid Liquid ◽  
Melting And Crystallization

Solid-liquid eutectic phase diagrams of mixtures of poly(oxyethylene) (M.w. 2 000) with hydroxy and methoxy endgroups, crystallizing in extended-chain macroconformation only, with glutaric acid, benzoic acid or 1,2-diphenylethane are given. The composition dependence of the melting temperature can be fitted by the Flory-Huggins equation. Interaction parameters X and interaction energy densities B evaluated from the diluent branch of the phase diagram are consistent with those obtained from the polymer branch provided the calorimetric value of enthalpy of polymer fusion is used in the latter computation. Measurements of small- and wide-angle X-ray scatterings showed a stacked lamellar structure of POE. Below the eutectic melting point, the long period of the polymer is almost independent of the diluent concentration. On raising temperature gradually from this melting point to the melting point of pure polymer, the increasing long period indicates the penetration of the diluent between the lamellae. As follows from SAXS measurements, the crystallinity of poly(oxyethylene) in the mixtures remains unchanged compared to that of the pure polymer.

Melting point depression study of polyacrylonitrile

1960 ◽  
Vol 43 (142) ◽  
pp. 467-488 ◽  
Author(s):  
W. R. Krigbaum ◽  
Noboru Tokita
Keyword(s):  
Melting Point ◽  
Melting Point Depression

Elastomer Structures and ‘Cold Crystallization’

1979 ◽  
Vol 52 (1) ◽  
pp. 207-212 ◽  
Author(s):  
M. Bruzzone ◽  
E. Sorta
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Melting Point ◽  
Natural Rubber ◽  
Crystallization Rate ◽  
Cold Crystallization ◽  
Structural Defects ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Abstract In a great number of applications an ideal elastomer should satisfy, to a certain extent, both of the following requirements: (1) nearly instantaneous crystallization upon application of strain (strain induced crystallization) and (2) slow or no crystallization when cooled at the temperature of maximum crystallization rate (cold induced crystallization). A noteworthy case of (2) is elastomer crystallization in a strained state. The connection between the points (1) and (2) has not been clearly understood up to now, but it is known that some crystallizable elastomers fulfil the requirements of both (1) and (2) better than others. From an experimental point of view, cold induced crystallization kinetics are substantially easier to measure than those of very fast strain induced crystallization. The phenomenon of cold induced crystallization in natural rubber, NR, has been known since the very beginning of elastomer technology and the tendency of natural rubber to crystallize by cooling has been overcome by crosslinking it with sulphur (vulcanization) without impairing its ability to crystallize by stretching (Goodyear, 1836). The synthesis of cis-polyisoprenes (IR) and cis-polybutadiene (BR) of different microstructural purity (different cis content) gave the possibility of changing the crystallization rate. It has also been reported that the very fast cold crystallization of trans-polypentenamer (TPA) could be reduced by lowering the trans content. The same fact had been observed earlier for trans-polychloroprene. There is a general agreement in postulating that the reduction of the crystallization rate, obtained either by cross-linking or by chain regularity reduction, can be linked with the lowering of the melting point. In both cases the low level of structural defects introduced in the chains does not affect the glass transition temperature in such a way as to vary the crystallization rate. The aim of this paper is to emphasize the importance of the variations of the glass transition temperature and melting point on the elastomeric cold crystallization rate and the way these may be used in planning new elastomer structures.

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