High-Field Electron Paramagnetic Resonance Reveals a Stable Glassy Fraction up to Melting in Semicrystalline Poly(dimethylsiloxane)
- Autores: Massa C.1, Pizzanelli S.2, Bercu V.3, Pardi L.1, Leporini D.1,4
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Afiliações:
- Istituto per i Processi Chimico-Fisici-Consiglio Nazionale delle Ricerche (IPCF-CNR)
- Istituto di Chimica dei Composti Organometallici-Consiglio Nazionale delle Ricerche (ICCOM-CNR)
- Department of Physics, University of Bucharest
- Dipartimento di Fisica “Enrico Fermi”, Universitá di Pisa
- Edição: Volume 48, Nº 8 (2017)
- Páginas: 827-840
- Seção: Original Paper
- URL: https://journals.rcsi.science/0937-9347/article/view/247790
- DOI: https://doi.org/10.1007/s00723-017-0903-z
- ID: 247790
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Resumo
The reorientation of the guest 4-methoxy-TEMPO (spin probe) in the disordered fraction of semicrystalline poly(dimethylsiloxane) (PDMS) is investigated by high-field electron paramagnetic resonance (HF-EPR) at 190 and 285 GHz. Accurate numerical simulations of the HF-EPR lineshapes evidence that the reorientation times of the spin probes are distributed between the melting temperature \(T_{\rm m}\) and \(T_{\rm m}\)—30 K. The distribution exhibits, in addition to a broad component, a narrow component with low mobility up to the PDMS melting point. It is shown that the temperature dependence of the reorientation time of the spin probes with low mobility is the same of the spin probes in glassy PDMS. The result suggests that the low-mobility fraction is localized in the so-called rigid amorphous fraction.
Sobre autores
Carlo Massa
Istituto per i Processi Chimico-Fisici-Consiglio Nazionale delle Ricerche (IPCF-CNR)
Email: dino.leporini@unipi.it
Itália, via G. Moruzzi 1, Pisa, 56124
Silvia Pizzanelli
Istituto di Chimica dei Composti Organometallici-Consiglio Nazionale delle Ricerche (ICCOM-CNR)
Email: dino.leporini@unipi.it
Itália, via G. Moruzzi 1, Pisa, 56124
Vasile Bercu
Department of Physics, University of Bucharest
Email: dino.leporini@unipi.it
Romênia, Str. Atomistilor 405, Magurele, Jud. Ilfov, Bucharest, 077125
Luca Pardi
Istituto per i Processi Chimico-Fisici-Consiglio Nazionale delle Ricerche (IPCF-CNR)
Email: dino.leporini@unipi.it
Itália, via G. Moruzzi 1, Pisa, 56124
Dino Leporini
Istituto per i Processi Chimico-Fisici-Consiglio Nazionale delle Ricerche (IPCF-CNR); Dipartimento di Fisica “Enrico Fermi”, Universitá di Pisa
Autor responsável pela correspondência
Email: dino.leporini@unipi.it
ORCID ID: 0000-0002-9429-0509
Itália, via G. Moruzzi 1, Pisa, 56124; Largo B. Pontecorvo 3, Pisa, 56127