Document Type : VSI: Honoring Prof. Yampolskii
Bundesanstalt für Materialforschung und -prüfung (BAM)
Bundesanstalt für Materialforschung und -prüfung
A.V. Topchiev Institute of Petrochemical Synthesis of Russian Academy of Science
Bundesanstalt für Materialforschung und -prüfung (BAM) Division 7.5 Technical Properties of Polymeric Materials
We report dielectric and calorimetric studies on metathesis and addition-type polytricyclononenes, both based on the same monomer bearing three pendant -OSiMe3 groups. For the addition-type polymer, dielectric spectroscopy reveals a ß*-process related to the microporosity, whereas for its metathesis counterpart, the segmental dynamics (α-process) manifests. Besides active dielectric processes, a significant conductivity contribution is detected for both samples which for the microporous addition-type polymer is three orders of magnitude greater than for the metathesis polymer. The broadband dielectric spectroscopy is complemented by detailed calorimetric investigations, comprising DSC, FSC, and TMDSC. The calorimetric methods detected the glass transition for the metathesis polymer in agreement with the observed dielectric α-process. We then compare the already reported gas transport properties for both polymers, setting them in correlation with the observed molecular mobility and conductivity behavior. The discussed results reflect significant differences in molecular mobility of the two polymers affecting the appearance of microporosity which strongly determines the gas transport properties.