Quantitative EPR study of poly(vinylidene fluoride) activated by electron beam treatment

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Mohsen Sadeghi Bogar - , Institut für Leichtbau und Kunststofftechnik (ILK) (Autor:in)
  • Sabine Beuermann - , Technische Universität Clausthal (Autor:in)
  • Evgenia Dmitirieva - , Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden (Autor:in)
  • Marco Drache - , Technische Universität Clausthal (Autor:in)
  • Uwe Gohs - , Institut für Leichtbau und Kunststofftechnik (ILK) (Autor:in)
  • Ulrich Kunz - , Technische Universität Clausthal, Energie-Forschungszentrum Niedersachsen (Autor:in)
  • Torben Lemmermann - , Technische Universität Clausthal, Energie-Forschungszentrum Niedersachsen (Autor:in)
  • Marco Rosenkranz - , Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden (Autor:in)
  • Maria Stehle - , Technische Universität Clausthal (Autor:in)
  • Carsten Zschech - , Leibniz-Institut für Polymerforschung Dresden (Autor:in)

Abstract

The electron paramagnetic resonance (EPR) spectra of poly (vinylidene fluoride) (PVDF) films were studied in order to identify type and intensity of trapped radicals after an electron treatment with 150 kGy in air at room temperature. The observed EPR spectra consist of superimposed spectra of eight different radicals. The individual spectra were simulated by first derivatives of normalized Gaussian functions including intensity, linewidth, g value, and hyperfine splitting constants of the unpaired electron with hydrogen or fluorine atoms in α or β positions. In addition, the number of trapped radicals was estimated using a standard sample of known spin concentrations. Although initially generated radicals tend to be converted to peroxy radicals in the presence of oxygen, the predominant radical is the CH-based mid-chain radical (–CF2–C*H-CF2-) with a relative intensity of 62.3%. This is attributed to CH-based radicals in the crystalline domains with low molecular mobility leading to an enhancement in its linewidth (ΔHpp ⁓ 3.6 mT). A fraction of 20.7% of all radicals are peroxy radicals with anisotropic g values, g = 2.0210 and g = 2.0095. The relative intensity of allyl, dienyl and polyenyl radicals amounts to 4.9%.

Details

OriginalspracheEnglisch
Aufsatznummer109421
FachzeitschriftRadiation Physics and Chemistry
Jahrgang184
PublikationsstatusVeröffentlicht - Juli 2021
Peer-Review-StatusJa

Externe IDs

Scopus 85103343035

Schlagworte

Schlagwörter

  • Air atmosphere, Electron beam modification, EPR analysis, Membrane, PVDF