Nanocomposites of Polyhedral Oligomeric Phenethylsilsesquioxanes and Poly(bisphenol A carbonate) as Investigated by Dielectric Spectroscopy
- Nanocomposites were prepared by solution blending of polyhedral oligomeric silsesquioxane with phenethyl substituents (PhenethylPOSS) into poly(bisphenol A carbonate) (PBAC). The nanocomposites were investigated by dielectric spectroscopy, differential scanning calorimetry (DSC) and density measurements. PhenethylPOSS shows one relaxation process, the α-relaxation, confirmed by DSC investigations. PBAC shows a β-relaxation at lower and an α-relaxation at higher temperatures. With increasing PhenethylPOSS content the α-relaxation of the composites shifts to lower temperatures. Thus, incorporation of PhenethylPOSS leads to a plasticization of PBAC due to a decrease of the packing density which is rationalized by density measurements. For higher concentrations of PhenethylPOSS (>10 wt %) the α-relaxation of the polycarbonate matrix splits into two peaks. Moreover, close to the α-relaxation of PhenethylPOSS a third process is observed. These results indicate a phase separation into a PBACNanocomposites were prepared by solution blending of polyhedral oligomeric silsesquioxane with phenethyl substituents (PhenethylPOSS) into poly(bisphenol A carbonate) (PBAC). The nanocomposites were investigated by dielectric spectroscopy, differential scanning calorimetry (DSC) and density measurements. PhenethylPOSS shows one relaxation process, the α-relaxation, confirmed by DSC investigations. PBAC shows a β-relaxation at lower and an α-relaxation at higher temperatures. With increasing PhenethylPOSS content the α-relaxation of the composites shifts to lower temperatures. Thus, incorporation of PhenethylPOSS leads to a plasticization of PBAC due to a decrease of the packing density which is rationalized by density measurements. For higher concentrations of PhenethylPOSS (>10 wt %) the α-relaxation of the polycarbonate matrix splits into two peaks. Moreover, close to the α-relaxation of PhenethylPOSS a third process is observed. These results indicate a phase separation into a PBAC matrix with a few percents of molecularly solved POSS and POSS-rich domains. These POSS-rich domains are surrounded by an interfacial layer of PBAC having a higher concentration of POSS than the matrix. A phase diagram is deduced providing a miscibility criterion. For the phase separated nanocomposites an interfacial polarization phenomena is observed. Using a simplified model the time constant of this process is correlated with the size of the PhenethylPOSS-rich domains and theire increasing size with the increase of the concentration of POSS.…
MetadatenAutor*innen: | Ning Hao, Martin BöhningORCiD, Harald Goering, Andreas SchönhalsORCiD |
---|
Dokumenttyp: | Zeitschriftenartikel |
---|
Veröffentlichungsform: | Verlagsliteratur |
---|
Sprache: | Englisch |
---|
Titel des übergeordneten Werkes (Englisch): | Macromolecules |
---|
Jahr der Erstveröffentlichung: | 2007 |
---|
Verlag: | American Chemical Society |
---|
Verlagsort: | Washington, DC |
---|
Jahrgang/Band: | 40 |
---|
Ausgabe/Heft: | 8 |
---|
Erste Seite: | 2955 |
---|
Letzte Seite: | 2964 |
---|
Freie Schlagwörter: | Broadband dielectric spectroscopy; Interfacial polarisation; Polyhedral oligomeric silsesquioxane (POSS); Polymer-based nanocomposites |
---|
ISSN: | 0024-9297 |
---|
ISSN: | 1520-5835 |
---|
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: | 07.05.2007 |
---|