Predictive relation for the ?-relaxation time of a coarse-grained polymer melt under steady shear.

ABSTRACT: We examine the influence of steady shear on structural relaxation in a simulated coarse-grained unentangled polymer melt over a wide range of temperature and shear rates. Shear is found to progressively suppress the ?-relaxation process observed in the intermediate scattering function, leading ultimately to a purely inertially dominated ?-relaxation at high shear rates, a trend similar to increasing temperature. On the basis of a scaling argument emphasizing dynamic heterogeneity in cooled liquids and its alteration under material deformation, we deduce and validate a parameter-free scaling relation for both the structural relaxation time ?? from the intermediate scattering function and the "stretching exponent" ? quantifying the extent of dynamic heterogeneity over the entire range of temperatures and shear rates that we can simulate.

SUBMITTER: Giuntoli A 

PROVIDER: S-EPMC7182423 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature