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Thermodynamics of polymeric fluids – effect of volume on the configurational entropy of chain molecules
Author(s) -
Abe Akihiro,
Takeda Takanori,
Hiejima Toshihiro,
Furuya Hidemine
Publication year - 2001
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/1521-3900(200109)174:1<383::aid-masy383>3.0.co;2-c
Subject(s) - thermodynamics , isobaric process , configuration entropy , molecule , entropy (arrow of time) , polymer , conformational entropy , isotropy , crystallization , excluded volume , chemistry , statistical physics , materials science , physics , organic chemistry , quantum mechanics
Various conformation‐dependent properties of chain molecules have been successfully treated within the rotational isomeric state approximation. The conformation entropy is one of such properties which can be readily defined by the partition function, the sum of all possible configurations of the chain. Flexible polymers often exhibit crystallization and in some cases liquid‐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 condition must be corrected for the volume change. The entropy separation involves a hypothetical assumption that the volume of the isotropic fluid may be compressed to that of the solid state without affecting the configurational part of the entropy of molecules. Finally thermodynamic significance of the conformation entropy in these transitions is emphasized on the basis of the critical studies of the entropy‐volume relation of chain molecules in the liquid state.