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An approach to thermodynamics of polymer flow based on internal state variables
Author(s) -
Astarita G.,
Sarti G. S.
Publication year - 1976
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760160705
Subject(s) - thermodynamics , entropy (arrow of time) , work (physics) , statistical physics , smoothness , materials science , flow (mathematics) , process (computing) , state variable , computer science , theoretical physics , mathematics , mechanics , physics , mathematical analysis , operating system
Two kinds of thermodynamic theories, which seem to be applicable to polymer deformation and flow, have been developed in the recent literature. One of these approaches utilizes entropy far from equilibrium as a primitive undefined concept. The alternate kind of theory involves the idea of a quasi‐static process as a primitive concept. In this work, an approach based on internal state variables (specifically, the micro structure of the polymeric material) is used to argue that both primitive concepts are in some sense legitimate on physical grounds. In particular, the legitimacy of the quasi‐static process concept is related to the smoothness of the function delivering the rate of change of the microstructure.