TY - CONF A1 - Yin, Huajie A1 - Konnertz, N. A1 - Böhning, Martin A1 - Schönhals, Andreas T1 - Molecular Mobility and Physical aging of SuperGlassy Polymers for Gas Separation Membranes as revealed by Dielectric Spectroscopy N2 - Polymeric membranes represent a cost- and energy efficient solution for gas separation. Recently superglassy polymers with high free volume outperform many conventional dense polymers in terms of gas permeability and selectivity. However, such materials with a high fractional free volume (FFV) are prone to pronounced physical aging. The initial microporous structures approach a denser state via local chain rearrangements which results in a dramatic reduction in the gas permeability. For the first time, dielectric spectroscopy with state-of-the-art high-resolution analyzers was employed to investigate the molecular mobility and physical aging of two representative groups of superglassy polymers: PIMs (PIM-1 & PIM-EA-TB) and Si-containing polynobornenes (PTCNSi1 & PTCNSi2). The dielectric behavior of the solution-cast polymeric films was measured by isothermal frequency scans during the different heating cycles in a broad temperature range. Structural relaxation of the films was observed during the measurements. Multiple dielectric processes following Arrhenius behavior were observed for all the investigated polymers. Moreover, they all showed conductivity in the glassy state. The significant increase in the conductivity with increasing temperature especially for PIMs is explained in terms of the formation of local intermolecular agglomerated structures due to interaction of π-electrons in aromatic moieties of the polymer backbone. T2 - 8th International Conference on Advanced Fibers and Polymer Materials CY - Shanghai, China DA - 08.10.2017 KW - Physical aging KW - Membranes KW - Broadband dielectric spectroscopy KW - Gas separation KW - Molecular mobility PY - 2017 AN - OPUS4-42877 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yin, Huajie A1 - Konnertz, N. A1 - Böhning, Martin A1 - Schönhals, Andreas T1 - Molecular mobility of super glassy polymers for gas separation membranes investigated by dielectric spectroscopy N2 - Super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP) or polymers with intrinsic microporosity (PIMs) play an important role in the current development of membrane materials for gas separation because of their high permeability and selectivity. Unfortunately, such materials which have a high fractional free volume (FFV) are prone to pronounced physical aging. The initial microporous structures approach a more dense state via local chain rearrangements which results in a dramatic reduction in the gas permeability. For the first time, broadband dielectric spectroscopy was employed to investigate the molecular dynamics of two representative groups of super glassy polymers: PIMs (PIM-1 & PIM-EA-TB) and Si-containing polynobornenes (PTCNSi1 & PTCNSi2). The dielectric behavior of the solution-cast polymeric films was measured by isothermal frequency scans during the different heating cycles in a broad temperature range. Structural relaxation of the films was observed during the measurements. Molecular relaxation processes following Arrhenius behavior with unusually high activation energies were observed for all the investigated polymers. The PIMs showed furthermore a significant conductivity in the glassy state which is explained with the formation of local intermolecular agglomerated structures due to interaction of π-electrons in aromatic moieties of the polymer backbone. T2 - 8th International Discussion Meeting on Relaxations in Complex Systems CY - Wisla, Poland DA - 23.07.2017 KW - Broadband dielectric spectroscopy KW - Molecular mobility KW - Physical aging KW - Membranes KW - Gas separation PY - 2017 AN - OPUS4-41162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -