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Entropy and melt fracture
Author(s) -
Balmer R. T.
Publication year - 1974
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.1974.070181020
Subject(s) - rheology , entropy (arrow of time) , second law of thermodynamics , thermodynamics , instability , fracture (geology) , materials science , mechanics , configuration entropy , statistical physics , physics , composite material
The onset of a well‐known flow instability commonly called “melt fracture” has remained one of the fundamental unsolved problems of polymer rheology. This work attempts to explain this phenomenon via a criterion based upon limitations to configurational entropy as dicated by the second law of thermodynamics. It is shown that the molecular orientation resulting from a sustained stress‐deformation rate field may be sufficient to affect the entropy balance of the system to the point of violation of the second law. The flow field then spontaneously changes, producing the condition called melt fracture, in a manner such as to prevent the violation of this law. Other theories on the mechanism of melt fracture are discussed in the context of the above criterion.