Paper Number
SM21 

Session
Polymer Solutions & Melts

Title
Tunable rheology of dendronized polymers

Presentation Date and Time
February 14, 2017 (Tuesday) 1:55

Track / Room
Track 5 / Snowy Egret

Authors (Click on name to view author profile)

1. Costanzo, Salvatore (Foundation for Research and Technology Hellas, Institute of Electronic Structure & Laser)
2. Scherz, Leon (Swiss Federal Institute of Technology, ETH Zurich, Department of Materials, Institute of Polymers)
3. Schweizer, Thomas (Swiss Federal Institute of Technology, Department of Materials, Institute of Polymers)
4. Kröger, Martin (Swiss Federal Institute of Technology, ETH, Department of Materials, Institute of Polymers)
5. Floudas, George (University of Ioannina and MPIP Mainz, Department of Physics)
6. Schlüter, Dieter A. (Swiss Federal Institute of Technology, ETH, Department of Materials)
7. Vlassopoulos, Dimitris (Foundation for Research and Technology - FORTH, Institute of the Electronic Structure and Laser)

Author and Affiliation Lines (in printed abstract book)
Salvatore Costanzo¹, Leon Scherz², Thomas Schweizer², Martin Kröger², George Floudas³, Dieter A. Schlüter², and Dimitris Vlassopoulos^1
1Institute of the Electronic Structure and Laser, Foundation for Research and Technology - FORTH, Heraklion, Crete 70013, Greece; ²Department of Materials, Institute of Polymers, Swiss Federal Institute of Technology, ETH Zurich, Zurich 8093, Switzerland; ³Department of Physics, University of Ioannina and MPIP Mainz, Ioannina 45110, Greece

Speaker / Presenter 
Costanzo, Salvatore

Text of Abstract
We present a systematic investigation of the rheology and packing of dendronized polymers (DPs) with varying generation and backbone degree of polymerization. Results reveal unusually long thermal equilibration times due to the tendency of DPs to minimize local density gradients and promote intermolecular correlations, akin to a Velcro type of behavior [1]. Results from X-ray scattering show increased lateral backbone-backbone correlations with a columnar arrangement of backbones and a liquid crystalline underlying order. Linear and nonlinear shear measurements provide further evidence for the Velcro-fastening response, with a rubbery plateau due to intermolecular interactions and FENE-like nonlinear response, both reflecting absence of entanglements [2]. Functionalization of DPs with ureido-pyrimidinone (UPy) groups, which enhance intermolecular bonding and affect the annealing kinetics, provides further support for this picture, as revealed by rheological measurements.

[1] Pasquino et al. Macromolecules 2012, 45, 8813 [2] Costanzo et al. Macromolecules 2016, 49, 7054