Broadband dielectric spectroscopy on the molecular dynamics in different generations of hyperbranched polyester
- Dielectric spectroscopy (10-2 Hz to 106 Hz) was employed to investigate the molecular dynamics of hyperbranched polyesters where the number of the generation is systematically varied from 2 to 5. As a first result, the dielectric properties depends strongly on the generation of the hyperbranched polymers. For higher generations (3 to 5) at temperatures below Tg two relaxation processes are observed, a γ-process at lower temperatures and a β-process at higher ones. The apparent activation energies are around 100 kJ/mol which seems to be too high for truly localized processes. For the Generation 2, only the γ-process is observed. For all investigated polymers the dielectric α-relaxation could not be observed because of strong conductivity effects. Therefore, the conductivity is systematically analyzed which obeys the peculiarities found to be characteristic for semiconducting disordered materials. Especially, the Barton/Nakajima/Namikawa relationship is found to be valid.
MetadatenAutor*innen: | G. Turky, S.S. Shaaban, Andreas SchönhalsORCiD |
---|
Dokumenttyp: | Zeitschriftenartikel |
---|
Veröffentlichungsform: | Verlagsliteratur |
---|
Sprache: | Englisch |
---|
Titel des übergeordneten Werkes (Englisch): | Journal of applied polymer science |
---|
Jahr der Erstveröffentlichung: | 2009 |
---|
Verlag: | Wiley InterScience |
---|
Verlagsort: | Hoboken, NJ |
---|
Jahrgang/Band: | 113 |
---|
Ausgabe/Heft: | 4 |
---|
Erste Seite: | 2477 |
---|
Letzte Seite: | 2484 |
---|
Freie Schlagwörter: | Molecular dynamics; Polyesters; Relaxation; Synthesis |
---|
DOI: | 10.1002/app.30046 |
---|
ISSN: | 0021-8995 |
---|
ISSN: | 1097-4628 |
---|
Verfügbarkeit des Dokuments: | Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access") |
---|
Bibliotheksstandort: | Sonderstandort: Publica-Schrank |
---|
Datum der Freischaltung: | 19.02.2016 |
---|
Referierte Publikation: | Ja |
---|
Datum der Eintragung als referierte Publikation: | 10.06.2009 |
---|