| Autor: |
Kilian, H. -G., Lagaly, G., Myasnikova, L., Marikhin, V. A., Kilian, H. G., Knechtel, W., Heise, B., Zrinyi, M. |
| Zdroj: |
Orientational Phenomena in Polymers; 1993, p60-80, 21p |
| Abstrakt: |
Large deformations of network-like systems are discussed. Such systems are characterized by the existence of equivalent subsystems of deformation isotropically linked with each other, operating as smallest structural units the shape of which is changed according to the law of an affine transformation. For describing large deformations of such "colloid systems" it is significant that the extremum principles of thermodynamics can be extended so as to allow a discussion of constrained equilibrium states. This has the consequence that strain invariant system elements in network-like polymer systems like real networks, glasses, filled rubbers or semicrystalline polymer system-elements are oriented so as to maximize the orientation entropy . This allows a concise thermodynamic interpretation. It is for example clear that in any constrained equilibrium state the maximum entropy is necessarily accompanied by an energy minimum. If internal constrained equilibrium is realizable even within very short periods of time these extremum is realizable even within very short periods of time these extremium principles should strictly be fulfilled. On the global level network-like systems should display universal features while the molecular structure comes into play on local scales. How both are interrelated and how they depend on the conditions of constrained equilibrium is discussed on the basis of representative examples. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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