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Title: Thermodynamic description and unidirectional solidification of eutectic organic alloys: II. (CH{sub 3}){sub 2}C(CH{sub 2}OH){sub 2}-(NH{sub 2})(CH{sub 3})C(CH{sub 2}OH){sub 2} system

Abstract

The temperature and enthalpy of melting of organic alloys from the binary system 2-amino-2-methyl-1,3-propanediol (AMPD) and neopentylglycol (NPG) were measured by means of differential scanning calorimetry (DSC) within the entire composition range. The analytical description of the Gibbs energies of pure AMPD and pure NPG was derived utilizing the data on temperature and enthalpy of transformations, and temperature dependencies of the heat capacity available in the literature. The phase diagram for the binary AMPD-NPG system was assessed via the CALPHAD approach using Thermo-Calc by simultaneously optimizing the thermodynamic and phase equilibrium data available in the literature and measured in the present work. An excellent agreement between the experimental and calculated data for the phase diagram as well as for the enthalpy of melting of the organic alloys was achieved. Experiments and calculations show that the binary AMPD-NPG system exhibits an eutectic reaction with the eutectic point at 378.3 K and 42.2 mol% NPG. The enthalpy of formation of the liquid, BCC and FCC phases derived from the optimisation proves an attractive interaction between dissimilar molecules in these phases. Unidirectional solidification of the eutectic alloy was performed in order to check the nature of the eutectic growth: We find that bothmore » solid phases grow with a non-facetted solid/liquid interface, but growth of a regular lamellar eutectic structure could not be observed.« less

Authors:
 [1];  [1];  [1];  [1]
  1. ACCESS e.V., Intzestrasse 5, D-52072 Aachen (Germany)
Publication Date:
OSTI Identifier:
20634784
Resource Type:
Journal Article
Journal Name:
Acta Materialia
Additional Journal Information:
Journal Volume: 52; Journal Issue: 17; Other Information: DOI: 10.1016/j.actamat.2004.07.013; PII: S1359-6454(04)00422-7; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1359-6454
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALCOHOLS; BCC LATTICES; CALORIMETRY; EUTECTICS; FCC LATTICES; FORMATION HEAT; MELTING; PHASE DIAGRAMS; SOLIDIFICATION; SPECIFIC HEAT; TRANSITION HEAT

Citation Formats

Witusiewicz, V T, Sturz, L, Hecht, U, and Rex, S. Thermodynamic description and unidirectional solidification of eutectic organic alloys: II. (CH{sub 3}){sub 2}C(CH{sub 2}OH){sub 2}-(NH{sub 2})(CH{sub 3})C(CH{sub 2}OH){sub 2} system. United States: N. p., 2004. Web. doi:10.1016/j.actamat.2004.07.013.
Witusiewicz, V T, Sturz, L, Hecht, U, & Rex, S. Thermodynamic description and unidirectional solidification of eutectic organic alloys: II. (CH{sub 3}){sub 2}C(CH{sub 2}OH){sub 2}-(NH{sub 2})(CH{sub 3})C(CH{sub 2}OH){sub 2} system. United States. https://doi.org/10.1016/j.actamat.2004.07.013
Witusiewicz, V T, Sturz, L, Hecht, U, and Rex, S. 2004. "Thermodynamic description and unidirectional solidification of eutectic organic alloys: II. (CH{sub 3}){sub 2}C(CH{sub 2}OH){sub 2}-(NH{sub 2})(CH{sub 3})C(CH{sub 2}OH){sub 2} system". United States. https://doi.org/10.1016/j.actamat.2004.07.013.
@article{osti_20634784,
title = {Thermodynamic description and unidirectional solidification of eutectic organic alloys: II. (CH{sub 3}){sub 2}C(CH{sub 2}OH){sub 2}-(NH{sub 2})(CH{sub 3})C(CH{sub 2}OH){sub 2} system},
author = {Witusiewicz, V T and Sturz, L and Hecht, U and Rex, S},
abstractNote = {The temperature and enthalpy of melting of organic alloys from the binary system 2-amino-2-methyl-1,3-propanediol (AMPD) and neopentylglycol (NPG) were measured by means of differential scanning calorimetry (DSC) within the entire composition range. The analytical description of the Gibbs energies of pure AMPD and pure NPG was derived utilizing the data on temperature and enthalpy of transformations, and temperature dependencies of the heat capacity available in the literature. The phase diagram for the binary AMPD-NPG system was assessed via the CALPHAD approach using Thermo-Calc by simultaneously optimizing the thermodynamic and phase equilibrium data available in the literature and measured in the present work. An excellent agreement between the experimental and calculated data for the phase diagram as well as for the enthalpy of melting of the organic alloys was achieved. Experiments and calculations show that the binary AMPD-NPG system exhibits an eutectic reaction with the eutectic point at 378.3 K and 42.2 mol% NPG. The enthalpy of formation of the liquid, BCC and FCC phases derived from the optimisation proves an attractive interaction between dissimilar molecules in these phases. Unidirectional solidification of the eutectic alloy was performed in order to check the nature of the eutectic growth: We find that both solid phases grow with a non-facetted solid/liquid interface, but growth of a regular lamellar eutectic structure could not be observed.},
doi = {10.1016/j.actamat.2004.07.013},
url = {https://www.osti.gov/biblio/20634784}, journal = {Acta Materialia},
issn = {1359-6454},
number = 17,
volume = 52,
place = {United States},
year = {Mon Oct 04 00:00:00 EDT 2004},
month = {Mon Oct 04 00:00:00 EDT 2004}
}