Thermodynamics of polymeric fluids - Effect of volume on the configurational entropy of chain molecules

Citation
A. Abe et al., Thermodynamics of polymeric fluids - Effect of volume on the configurational entropy of chain molecules, MACRO SYMP, 174, 2001, pp. 383-391
Citations number
40
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
MACROMOLECULAR SYMPOSIA
ISSN journal
1022-1360 → ACNP
Volume
174
Year of publication
2001
Pages
383 - 391
Database
ISI
SICI code
1022-1360(200108)174:<383:TOPF-E>2.0.ZU;2-X
Abstract
Various conformation-dependent properties of chain molecules have been succ essfully treated within the rotational isomeric state approximation. The co nformation entropy is one of such properties which can be readily defined b y the partition function, the sum of all possible configurations of the cha in. Flexible polymers often exhibit crystallization and in some cases liqui d-crystallization as well. In these first-order transitions, changes in the spatial arrangement of polymer chains are considered to be a major factor involved. In order to explicitly determine the conformational contribution to the melting entropy, the latent entropy observed under the isobaric cond ition must be corrected for the volume change. The entropy separation invol ves a hypothetical assumption that the volume of the isotropic fluid may be compressed to that of the solid state without affecting the configurationa l part of the entropy of molecules. Finally thermodynamic significance of t he conformation entropy in these transitions is emphasized on the basis of the critical studies of the entropy-volume relation of chain molecules in t he liquid state.