Elongational Flow of Blends of Long and Short Polymers: Effective Stretch Relaxation Time

Abstract

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

Numerical prediction of nonlinear rheology of branched polymer melts

“…The reason is that constraint release modes, corresponding to structure on length scales smaller than this flow-tube, relax much faster than the flow time and so are not stretched; only modes corresponding to structure on scales larger than the flow-tube are stretched. However, recent investigations into bimodal blends [Auhl et al (2009);Read et al (2012)] indicate that stretch relaxation dynamics in the presence of constraint release can give rise to complicated and nonintuitive dynamics. The question arises as to whether branchpoint withdrawal, leading to maximum stretch, should be considered within the flow tube or perhaps within some smaller tube.…”

Spontaneous Breakup of Extended Monodisperse Polymer Melts

“…These ruptures agree with experimental observations. DOI There have been remarkable advances in the understanding of polymer dynamics over the past few years [1][2][3][4][5][6], all based on tube models. This is a result of the appearance of new experimental techniques [7,8].…”

i-Rheo: Measuring the materials' linear viscoelastic properties “in a step”!

“…The LVE properties of monodisperse amorphous linear polymer melts and their blends [14][15][16] represent a validation tool for a number of constitutive models (e.g., [17][18][19][20][21][22]) aimed at predicting the rheological behavior of complex polymer systems (e.g., [23][24][25]). This is because of their "simple" topological structure (i.e., entangled polymer chains), which has allowed, over the past 40 years, the establishment of a solid theoretical framework built on the pioneering tube model developed by de Gennes [26] and Doi and Edwards [27].…”