BPCPPDYSOE21 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 14: Poster Session II - Complex Fluids and Perovskites
CPP 14.1: Poster
Dienstag, 23. März 2021, 16:30–18:30, CPPp
Direct Observation of the Time-dependent Dynamic Tube Dilation in Entangled Polymer Blends — •Paula Malo de Molina1,2, Angel Alegría1,3, Jürgen Allgeier4, Margarita Kruteva4, Ingo Hoffmann5, Sylvain Prévost5, Michael Monkenbusch4, Dieter Richter4, Arantxa Arbe1, and Juan Colmenero1,3,6 — 1Materials Physics Center (CSIC-UPV/EHU), San Sebastian, Spain — 2IKERBASQUE - Basque Foundation for Science, Bilbao, Spain — 3Departamento de Física de Materiales (UPV/EHU), San Sebastian, Spain — 4Forschungszentrum Jülich GmbH, Jülich, Germany — 5Institut Laue-Langevin, Grenoble, France — 6Donostia International Physics Center, San Sebastián, Spain
The viscoelastic properties of high molecular weight polymers are given by their entanglement dynamics. In asymmetric polymer blends, the finite lifetime of constraints leads to a dilation of the tube but how does the tube dilate? The effective terminal tube dilation of the long chains can be determined from macroscopic techniques such as dielectric spectroscopy (DS) and rheology, which cannot resolve the time evolution of the tube diameter at the nm-scale. Here, we exploit (i) the possibility of isotopic (H/D) labeling and (ii) the spatial and time resolution of neutron spin echo (NSE) to directly probe the time-dependent tube dilation for long linear entangled chains in model blends with smaller isofrictional linear chains and small star polymers. By combining NSE with rheology and DS on the additive, the characteristic time that governs tube dilation is identified as the terminal time of the additive.