Dynamic arrest in polymer melts: competition between packing and intramolecular barriers

We present molecular dynamics simulations of a simple model for polymer melts with intramolecular barriers. We investigate structural relaxation as a function of the barrier strength. Dynamic correlators can be consistently analyzed within the framework of the mode coupling theory of the glass trans...

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Detalles Bibliográficos
Autores: Bernabei, Marco, Moreno, Ángel J., Colmenero, Juan
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2008
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/50454
Acceso en línea:https://hdl.handle.net/2445/50454
Access Level:acceso abierto
Palabra clave:Dinàmica molecular
Polímers
Macromolècules
Matèria condensada
Molecular dynamics
Polymers
Macromolecules
Condensed matter
Descripción
Sumario:We present molecular dynamics simulations of a simple model for polymer melts with intramolecular barriers. We investigate structural relaxation as a function of the barrier strength. Dynamic correlators can be consistently analyzed within the framework of the mode coupling theory of the glass transition. Control parameters are tuned in order to induce a competition between general packing effects and polymer-specific intramolecular barriers as mechanisms for dynamic arrest. This competition yields unusually large values of the so-called mode coupling theory exponent parameter and rationalizes qualitatively different observations for simple bead-spring and realistic polymers. The systematic study of the effect of intramolecular barriers presented here also establishes a fundamental difference between the nature of the glass transition in polymers and in simple glass formers.