Dynamics and rheology of entangled linear polymers

Koga, Jiro; Kimura, Kei; Homma, Shunji

doi:10.1016/j.ces.2007.01.025

Cited by 7 publications

(6 citation statements)

References 15 publications

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“…Despite the difficulties associated with the mathematical description of the two mechanisms (CLF and CR), numerous extensions and refinements of the original model have been considered. [20][21][22][23][24][25][26][27] For example, to account for CLF effects, a number of investigators have proposed to use a positiondependent curvilinear diffusion coefficient in the diffusion equation. [20][21][22] Others have added a reaction-like term to the diffusion equation with a position-dependent rate constant (following a similar approach to the same problem by Doi 3,14 ).…”

Section: Introductionmentioning

confidence: 99%

Projection of atomistic simulation data for the dynamics of entangled polymers onto the tube theory: calculation of the segment survival probability function and comparison with modern tube models

2011

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Section: Introductionmentioning

confidence: 99%

Projection of atomistic simulation data for the dynamics of entangled polymers onto the tube theory: calculation of the segment survival probability function and comparison with modern tube models

2011

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“…As reported in the literature,3, 9–11 however, for systems with a finite MW, the effect of CLFs on chain dynamics and thus on the overall viscoelastic properties of the system can be significant. Several theoretical efforts have been proposed to take account of CLFs: following Doi's proposition,11 one approach11, 13–15 has been to introduce a reaction‐like term into the diffusion equation of the original reptation theory with a position‐dependent rate constant; a second approach16–18 has been to directly employ into the diffusion equation a position‐dependent curvilinear diffusion coefficient.…”

Section: Introductionmentioning

confidence: 99%

Toward an Improved Description of Constraint Release and Contour Length Fluctuations in Tube Models for Entangled Polymer Melts Guided by Atomistic Simulations

Stephanou

Baig

Mavrantzas

2011

Macro Theory & Simulations

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By mapping atomistic trajectories accumulated in the course of long molecular dynamics simulations onto the tube model for model mono‐ and bidisperse polyethylene and cis‐1,‐4 and trans‐1,4‐polybutadiene melts, we have computed contributions to chain dynamics in entangled polymers from pure reptation, contour length fluctuation, and constraint release. We find that the tube diameter is the same in the matrices with molecular weight (MW) above the characteristic value Me for the formation of entanglements, but becomes larger in the matrices with MW below Me, in agreement with the Viovy et al. hypothesis. Additional results for the segment survival probability function ψ(s,t) have been used to propose modifications to the dual constraint model of Pattamaprom et al. and to the Leygue et al. model.magnified image

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“…The relation between the shift factor and the reduced volume was used to predict the long-term behavior of the materials from a minimum (at least two sets) of data. To describe the dynamics of the linear polymer in monodisperse melts, Koga et al 11 presented a reaction-diffusion type equation that contained contributions from reptation and contour-length fluctuation on the basis of the tube model. The relaxation function calculated from this equation was in good agreement with the experimental results of the dielectric relaxation function and also gave the stress-relaxation function in binary blends by use of a semi-empirical scheme called double reptation.…”

Section: Introductionmentioning

confidence: 99%

Stress‐relaxation behavior of natural rubber/polystyrene and natural rubber/polystyrene/natural rubber‐graft‐polystyrene blends

Asaletha¹,

Bindu

Aravind

et al. 2008

J of Applied Polymer Sci

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ABSTRACT:We studied the stress-relaxation behavior of natural rubber (NR)/polystyrene (PS) blends in tension. The effects of strain level, composition, compatibilizer loading, and aging on the stress-relaxation behavior were investigated in detail. The dispersed/matrix phase morphology always showed a two-stage mechanism. On the other hand, the cocontinuos morphology showed a singlestage mechanism. The addition of a compatibilizer (NR-g-PS) into 50/50 blends changed the blend morphology to a matrix/dispersed phase structure. As a result, a two-step relaxation mechanism was found in the compatibilized blends. A three-stage mechanism was observed at very high loadings of the compatibilizer (above the critical micelle concentration), where the compatibilizer formed micelles in the continuous phase. The aged samples showed a two-stage relaxation mechanism. The rate of relaxation increased with strain levels. The aging produced interesting effects on the relaxation pattern. The rate of relaxation increased with temperature due to the degradation of the samples.

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Dynamics and rheology of entangled linear polymers

Cited by 7 publications

References 15 publications

Projection of atomistic simulation data for the dynamics of entangled polymers onto the tube theory: calculation of the segment survival probability function and comparison with modern tube models

Projection of atomistic simulation data for the dynamics of entangled polymers onto the tube theory: calculation of the segment survival probability function and comparison with modern tube models

Toward an Improved Description of Constraint Release and Contour Length Fluctuations in Tube Models for Entangled Polymer Melts Guided by Atomistic Simulations

Stress‐relaxation behavior of natural rubber/polystyrene and natural rubber/polystyrene/natural rubber‐graft‐polystyrene blends

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