Almdal, Kristoffer

Dorokhin, Andriy

Hassager, Ole

Hengeller, Ludovica

Huang, Qian

Kirkensgaard, Jacob JK

Mortensen, Kell

Liquid bridges occur in a variety of situations in nature - yet our understanding of the dynamics and stability is very limited. Examples of liquid bridges are the process used byspiders to form draglines and the process used by cats lapping milk. We have an extendedprogram aiming to provide generic knowledge about the process in which macromolecular fluidfilaments are extended and stretched and show how the extensional properties are related to theproperties on individual molecules. We combine structural and rheological studies of a series ofmodel polymers with different composition and architectures. The project entails synthesizingmodel polymer systems of precisely known molecular architecture, subjecting these materials tocontrolled extensional flows and to measure the molecular deformation under controlled flowsituation by SANS. Neutron contrast is obtained using specific deuterium labeled molecules.We have targeted different systems: first a “simple” sample of homogeneous high-molar masspolymers, where only the central part of a fraction of the polymers were D-labelled with the aimto highlight the polymer deformation and avoid influence of fast relaxation near the polymerends [1]. Another example is a bimodal mixture of linear polymer chains with respectively highand low molar mass, and we have studied samples with more complex geometry, includingPOM-POM architecture. The 2D-SANS data have typically Lozenge shaped contour which isanalyzed using the Read- McLeish-model of stretched polymer network [2]. The structure andrheology are measured both as a function of stain flow velocity, final Hencky strain ratio andduring the relaxation after cessation of extensional flow

Online Research Database In Technology

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Nov 08, 2017Entangled Polymer Melts in Extensional Flow - Characterization by CombinedRheology and Small-Angle Neutron ScatteringMortensen, Kell; Kirkensgaard, Jacob JK; Hassager, Ole; Hengeller, Ludovica; Huang, Qian; Almdal,Kristoffer; Dorokhin, AndriyPublication date:2015Document VersionPublisher's PDF, also known as Version of recordLink back to DTU OrbitCitation (APA):Mortensen, K., Kirkensgaard, J. J. K., Hassager, O., Hengeller, L., Huang, Q., Almdal, K., & Dorokhin, A. (2015).Entangled Polymer Melts in Extensional Flow - Characterization by Combined Rheology and Small-AngleNeutron Scattering. Abstract from 16th Conference on Small Angle Scattering (SAS 2015), Berlin, Germany.ENTANGLED POLYMER MELTS IN EXTENSIONAL FLOW RHEOLOGY AND SMALL-ANGLE NEUTRON SCATTERING  Kell Mortensena, Jacob JK Kirkensgaarda, Ole Hassager b, Ludovica Hengeller b, Qian Huangb, Kristoffer Almdalc and Andriy Dorokhinc,aNiels Bohr Institute, University of Copenhagen, Denmark,bChem. Engineering. Technical University of Denmark, Lyngby, DenmarkcNanotech, Technical University of Denmark, Lyngby, Denmark Liquid bridges occur in a variety of situations in nature - yet our understanding of the dynamics and stability is very limited. Examples of liquid bridges are the process used by spiders to form draglines and the process used by cats lapping milk. We have an extended program aiming to provide generic knowledge about the process in which macromolecular fluid filaments are extended and stretched and show how the extensional properties are related to the properties on individual molecules. We combine structural and rheological studies of a series of model polymers with different composition and architectures. The project entails synthesizing model polymer systems of precisely known molecular architecture, subjecting these materials to controlled extensional flows and to measure the molecular deformation under controlled flow situation by SANS. Neutron contrast is obtained using specific deuterium labeled molecules.  We have targeted different systems: first a “simple” sample of homogeneous high-molar mass polymers, where only the central part of a fraction of the polymers were D-labelled with the aim to highlight the polymer deformation and avoid influence of fast relaxation near the polymer ends [1]. Another example is a bimodal mixture of linear polymer chains with respectively high and low molar mass, and we have studied samples with more complex geometry, including POM-POM architecture. The 2D-SANS data have typically Lozenge shaped contour which isanalyzed using the Read- McLeish-model of stretched polymer network [2]. The structure and rheology are measured both as a function of stain flow velocity, final Hencky strain ratio and during the relaxation after cessation of extensional flow.References [1] Ole Hassager, Kell Mortensen, Anders Bach, Kristoffer Almdal, Henrik Koblitz Rasmussen, Wim Pyckhout-Hintzen. Rheologica Acta 51, (2012) 385.  [2] D. J. Read, T. C. B. McLeish. Macromolecules 30 (1997) 6376. _____________________________________________________________________________Submitting Author: kell@nbi.dk Figure 1: Samples as available after being exposed to different extensional flow rates. Figure 2: Schematic illustration of the molecules to be studies and the SANS experiment.WEDNESDAYORAL PRESENTATIONS - SAS2015Wed-P2: Polymers 11:20

Entangled Polymer Melts in Extensional Flow - Characterization by Combined Rheology and Small-Angle Neutron Scattering

Kirkensgaard, Jacob Judas Kain

Dorokhin, Andeiy

Copenhagen University Research Information System

http://orbit.dtu.dk/ws/files/121765194/Entangled_Polymer_Melts_in_Extensional_Flow_Characterization_by_Combined_Rheology_and_Small_Angle_Neutron_Scattering.pdf

Entangled Polymer Melts in Extensional Flow - Characterization by Combined Rheology and Small-Angle Neutron Scattering

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