Electronic Resource
College Park, Md.
:
American Institute of Physics (AIP)
The Journal of Chemical Physics
97 (1992), S. 3710-3721
ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We develop a theory of the dynamics of flexible linear polymers in a melt composed of macromolecules of two molecular weights and of the same chemical species. A polymer is represented by a freely jointed chain that moves by two dynamical processes. The first is a local jump motion that may be blocked by obstacles, and the second is a slithering mode that mimics reptation. The dynamics of the obstacles are determined self-consistently by an ansatz that associates their relaxation with the dynamics of the slowest mode of conformational relaxation of a chain. The calculations of the autocorrelation function of the end-to-end vector and of the mean squared displacement of the center of mass are related exactly to the solution of a random walk problem with dynamical disorder. We calculate the necessary random walk propagator by applying the dynamical effective medium approximation. Calculations of the dependence of the self-diffusion coefficient of both components on blend composition and on molecular weights are presented. The theory is shown to provide a unified description of diffusion in the unentangled and entangled regimes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.462953
Permalink
|
Location |
Call Number |
Expected |
Availability |