The elasticity of polymers is mostly due to entropic effect. The polymer chains want to stay random and form ball shape to increase the configurations. When the polymer chains are stretched, the chains deform in the stretched direction, form elliptical shape for example and decrease the configurations. This process is reversible, the elasticity is entropic, and the deformation is usually big. In contrast, for metals and ceramics, the elasticity is due to the stretching of bonds, which is enthalpic and usually the deformation is small.
Does that mean entropic is isentropic? n in enthalpic hmm wer the enthalpi comes into picture? Both should be entropic i guess..one isentropic the other non isentropic. ??
Holzapfel: Nonlinear solid mechanics
Google Books permalink: http://books.google.com/books?id=_ZkeAQAAIAAJ
There's a table on Page 310 (Section 7.1) that explicitly addresses your question.
In reply to Holzapfel: Nonlinear solid mechanics by Xiang Chen
Thanks !
Thanks!!!
Enthalpic and Entropic elasticity
The elasticity of polymers is mostly due to entropic effect. The polymer chains want to stay random and form ball shape to increase the configurations. When the polymer chains are stretched, the chains deform in the stretched direction, form elliptical shape for example and decrease the configurations. This process is reversible, the elasticity is entropic, and the deformation is usually big. In contrast, for metals and ceramics, the elasticity is due to the stretching of bonds, which is enthalpic and usually the deformation is small.
In reply to Enthalpic and Entropic elasticity by Lihua Jin
Thanks ! A further Q
Thank you ... :)
Does that mean entropic is isentropic? n in enthalpic hmm wer the enthalpi comes into picture? Both should be entropic i guess..one isentropic the other non isentropic. ??