Regensburg 2019 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 17: Poster Session I

CPP 17.31: Poster

Montag, 1. April 2019, 17:30–19:30, Poster B1

Multiple Glassy Dynamics of an Asymmetric PVME/PS Blend Investigated by Broadband Dielectric and Specific Heat Spectroscopy — •Paulina Szymoniak, Sherif Madkour, and Andreas Schönhals — Bundesanstalt für Materialforschung und prüfung (BAM), Berlin, Germany

Over the past decades research on the molecular dynamics of miscible polymer blends is of topical interest in the literature, to understand the segmental mobility of individual components, as it is affected by blending. In general, miscible polymer blends exhibit a complex dynamic behavior. For an A/B blend the relaxation times of component A and component B are affected by the spatial local compositional heterogeneity, present in binary systems on a microscopic level, regardless of the macroscopic homogeneity. Here, a combination of broadband dielectric and specific heat spectroscopy was employed to study the dynamically asymmetric PVME/PS blend with seven different compositions, focusing on samples with high PS contents. Considering that PS is dielectrically invisible, BDS is a powerful technique to study the response of PVME, as it is affected by PS segments. Here, three separate relaxation processes were found by dielectric investigations, related to confined or constrained PVME segments due to the spatial local compositional heterogeneities, which is in contrary to the previous literature findings [1]. Moreover, the dielectric data was compared with results obtained by specific heat spectroscopy, where a fourth relaxation process was found, due to the cooperative fluctuations of PVME and PS. [1] Colmenero, J., Arbe, A. Soft Matter, 2007, 3, 1474.