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Entropy–enthalpy compensation in solution properties of solutes at infinite dilution in nonpolar polymers
Author(s) -
Huang JanChan
Publication year - 2007
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.25766
Subject(s) - enthalpy , thermodynamics , enthalpy change of solution , enthalpy of mixing , enthalpy of vaporization , chemistry , solubility , miscibility , polymer , flory–huggins solution theory , materials science , organic chemistry , physics
The knowledge of the Flory–Huggins interaction parameter, χ, between organic liquids and polymers is very important in the study of their miscibility. From the temperature dependency of χ the enthalpy and residual entropy of solution can be determined. In this study literature data of thirty‐two solutes, ranging from alkanes to alcohols, at infinite dilution in isotatic polypropylene, poly(ethyl ethylene), and poly(dimethylsiloxane), were tested and linear entropy–enthalpy compensation was observed. The plot of residual free energy versus enthalpy of solution was also linear, with a lower correlation coefficient than the entropy–enthalpy plot. The range of enthalpy of solution was wider than those of the size corrected free energy of solution. In nonpolar solvents the enthalpy of solution reflected largely the interaction within the solute liquid state, and showed a linear trend with respect to solute cohesive energy density for n ‐alcohols. The wide range of enthalpy of solution suggests the use of a two‐dimensional solubility parameter model to correlate the enthalpy of solution. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1241–1247, 2007