Document Type
Article
Publication Date
January 2008
Abstract
The thermodynamical aspects of polymeric liquids subjected to uniaxial elongational flow are examined using atomistically detailed nonequilibrium Monte Carlo simulations. In particular, attention is paid to the energetic effects, in addition to the entropic ones, which occur under conditions of extreme deformation. Atomistic nonequilibrium Monte Carlo simulations of linear polyethylene systems, ranging in molecular length from C24 to C78 and for temperatures from 300 to 450 K, demonstrate clear contributions of energetic effects to the elasticity of the system. These are manifested in a conformationally dependent heat capacity, which is significant under large deformations. Violations of the hypothesis of purely entropic elasticity are evident in these simulations, in that the free energy of the system is demonstrated to be composed of significant energetic effects under high degrees of orientation. These arise mainly from favorable intermolecular side-to-side interactions developing in the process of elongation due to chain uncoiling and alignment in the direction of extension.
Recommended Citation
Keffer, David; Ionescu, T. C.; Mavrantzas, V. G.; and Edwards, B. J., "Atomistic Simulation of Energetic and Entropic Elasticity in Short-chain Polyethylenes" (2008). Chemical and Biomolecular Engineering Publications and Other Works.
http://trace.tennessee.edu/utk_chembiopubs/82
Included in
Complex Fluids Commons, Membrane Science Commons, Nanoscience and Nanotechnology Commons, Polymer Science Commons, Thermodynamics Commons, Transport Phenomena Commons
Comments
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