منابع مشابه
Advances in Modeling of Polymer Melt Rheology
T he development of theories to predict the rheological (i.e., flow) properties of densely packed polymers in the melt or solution state is important because such theories might enable rational design of polymer processing methods for shaping polymers into products, and because they can be used in rheological characterization of polymer molecular weight and long-chain branching. These are impor...
متن کاملIndividual entanglements in a simulated polymer melt.
Since the first theories of rubber elasticity, the notion of entanglement between polymer chains has been a central component [1]. Conceptually these entanglements are viewed as discrete constraints that limit the configurations of the chains, reduce their randomness, and thus contribute to the entropic stress in the rubber. These same entanglements are thought to be present in polymer melts. H...
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– We investigate the static shear viscosity on the sol side of the vulcanization transition within a minimal mesoscopic model for the Rouse-dynamics of a randomly crosslinked melt of phantom polymers. We derive an exact relation between the viscosity and the resistances measured in a corresponding random resistor network. This enables us to calculate the viscosity exactly for an ensemble of cro...
متن کاملLocal Strain Relaxation Dictates Polymer Melt Viscosity
A remarkable manifestation of slow dynamics in dense polymeric systems is that their viscosity scales with their molecular weight as a power-law, with the “viscosity exponent” mη, experimentally measured to be 3.4 ± 0.2. Following De Gennes’ work in 1971, current understanding of this slow dynamics is based upon an effective single-polymer theory that pictures every polymer in such systems movi...
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We analyze dynamical heterogeneities in a simulated ‘‘bead-spring’’ model of a nonentangled, supercooled polymer melt. We explore the importance of chain connectivity on the spatially heterogeneous motion of the monomers. We find that when monomers move, they tend to follow each other in one-dimensional paths, forming strings as previously reported in atomic liquids and colloidal suspensions. T...
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ژورنال
عنوان ژورنال: Journal of Applied Polymer Science
سال: 1963
ISSN: 0021-8995,1097-4628
DOI: 10.1002/app.1963.070070634