Regensburg 2022 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 49: Polymer and Molecular Dynamics, Friction and Rheology

CPP 49.1: Vortrag

Freitag, 9. September 2022, 11:30–11:45, H39

Molecular Mobility and Physical Aging in Polymers of Intrinsic Microporosity (PIM-1) Revisited: A Big Glassy World — •Farnaz Emamverdi, Martin Böhning, and Andreas Schönhals — Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany

Polymers of Intrinsic Microporosity (PIMs) are promising candidates for the active layer in gas separation membranes because of their high permeability and reasonable permselectivity. However, PIMs suffer from a decrease in performance with time due to physical aging. The initial microporous structures approach a denser state via local rearrangements, leading to a reduction of the permeability. Hence a characterization of the molecular mobility in these materials can provide valuable information about physical aging. In this work, the dielectric behavior of PIM-1 films and their behavior upon heating (aging) were revisited during different heating/cooling cycles in a broad temperature range between 133 K and 523 K. In addition, the obtained results were compared with data of samples that were annealed at ambient temperatures for different time. Multiple dielectric processes were observed like different relaxations due to local fluctuations and a Maxwell-Wagner-Sillars polarization effects due to the microporosity. The temperature dependence of the rates of all the processes follows the Arrhenius law where the estimated activation energy depends on the process. The influence of the thermal history on the processes is discussed in detail.