Onset of entanglements revisited. Dynamical analysis

Lahmar, F; Tzoumanekas, C; Theodorou, DN; Rousseau, B

dc.contributor.author	Lahmar, F	en
dc.contributor.author	Tzoumanekas, C	en
dc.contributor.author	Theodorou, DN	en
dc.contributor.author	Rousseau, B	en
dc.date.accessioned	2014-03-01T01:31:35Z
dc.date.available	2014-03-01T01:31:35Z
dc.date.issued	2009	en
dc.identifier.issn	0024-9297	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19828
dc.subject	Dynamic Analysis	en
dc.subject.classification	Polymer Science	en
dc.subject.other	Bottom up approach	en
dc.subject.other	Carbon atoms	en
dc.subject.other	Chain contours	en
dc.subject.other	Chain stiffness	en
dc.subject.other	Chain-length dependence	en
dc.subject.other	Coarse grained models	en
dc.subject.other	Coarse Graining	en
dc.subject.other	Coarse-grained	en
dc.subject.other	Continuous transitions	en
dc.subject.other	Dissipative particle dynamics	en
dc.subject.other	Dynamical analysis	en
dc.subject.other	Dynamical transition	en
dc.subject.other	Global dynamics	en
dc.subject.other	Length scale	en
dc.subject.other	Long chains	en
dc.subject.other	Monodisperse systems	en
dc.subject.other	Nonbonded interaction	en
dc.subject.other	Parametrizations	en
dc.subject.other	Polymer chains	en
dc.subject.other	Polymer dynamics	en
dc.subject.other	Power law	en
dc.subject.other	Primitive path	en
dc.subject.other	Reptation	en
dc.subject.other	Reptation model	en
dc.subject.other	Repulsive potentials	en
dc.subject.other	Rouse model	en
dc.subject.other	Rouse modes	en
dc.subject.other	Self-Diffusion	en
dc.subject.other	Static and dynamic	en
dc.subject.other	Topological analysis	en
dc.subject.other	Topological constraints	en
dc.subject.other	Underlying systems	en
dc.subject.other	Chain length	en
dc.subject.other	Chains	en
dc.subject.other	Dynamics	en
dc.subject.other	Polymer melts	en
dc.subject.other	Polymers	en
dc.subject.other	Mathematical models	en
dc.title	Onset of entanglements revisited. Dynamical analysis	en
heal.type	journalArticle	en
heal.identifier.primary	10.1021/ma9011329	en
heal.identifier.secondary	http://dx.doi.org/10.1021/ma9011329	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	In a series of two papers, we study the onset of entanglements and the transition from Rouse-type to reptation dynamics, in the context of dissipative particle dynamics (DPD) simulations of a coarse-grained polymer melt. A set of monodisperse systems with increasing chain length is examined. We consider both static and dynamic aspects of the problem. Part I, the preceding paper (10.1021/ma901131c), presents a topological analysis of our systems. It deals with the continuous transition from unentangled to entangled topology, as chain length increases, at the level of primitive paths (PPs). In part II, this paper, we present the dynamics of our systems, and a comparison between topological and dynamical analysis. We utilize a coarsegrained model of polyethylene, based on the blob (or bead) picture of a polymer chain. The conservative potentials describing bead interactions are derived by a bottom-up approach. Each bead corresponds to 20 carbon atoms. Because of the large coarse-graining level, beads can easily overlap and chain contours can cross each other. We maintain chain uncrossability by introducing a segmental repulsive potential (SRP), adapted to our model. It is demonstrated that suitable parametrization of this potential can reproduce the dynamical transition from Rouse to reptation dynamics. For short chain unentangled systems, we observe a deviation from the pure Rouse behavior, attributed to the presence of chain stiffness, nonbonded interactions, and chain uncrossability, which are not considered by the Rouse model. For long chain systems, global dynamics is typical of reptation. The chain length dependence of viscosity and self-diffusion is described by power laws, with exponents equal to +3.2 and -2.3, respectively. A global and local (Rouse-mode) dynamical analysis, a static topological analysis, and the comparison between them, shows that topological constraints alter polymer dynamics at length scales much shorter than the length scales implied by the reptation model. This is evidenced by a slowing down of Rouse modes, which is maximum at the length scale where the underlying system of interpenetrating PPs appears as a network of topological constraints. © 2009 American Chemical Society.	en
heal.publisher	AMER CHEMICAL SOC	en
heal.journalName	Macromolecules	en
dc.identifier.doi	10.1021/ma9011329	en
dc.identifier.isi	ISI:000270461600035	en
dc.identifier.volume	42	en
dc.identifier.issue	19	en
dc.identifier.spage	7485	en
dc.identifier.epage	7494	en