Abstract
The dynamic relaxation characteristics of poly(ether imide) and poly(methyl methacrylate) nanocomposites based on native and surface-modified (i.e., hydrophobic) fumed silicas were investigated by dynamic mechanical analysis and dielectric spectroscopy. The nanocomposites displayed a dual glass transition behavior in the dynamic mechanical studies encompassing a bulk polymer glass transition (close to Tg for the unfilled polymer), and a second, higher-temperature transition reflecting relaxation of polymer chain segments constrained owing to their proximity to the particle surface. The position and intensity of the higher-temperature transition varied with particle loading and surface chemistry, and reflected the relative populations of segments constrained or immobilized at the particle-polymer interface. Dielectric measurements, which were used to probe the time-temperature response across the local sub-glass relaxations, indicated no variation in relaxation characteristics with particle loading.
| Original language | English |
|---|---|
| Pages (from-to) | 5245-5254 |
| Number of pages | 10 |
| Journal | Polymer |
| Volume | 51 |
| Issue number | 22 |
| DOIs | |
| State | Published - Oct 15 2010 |
Bibliographical note
Funding Information:Acknowledgment is made to the Donors of the American Chemical Society Petroleum Research Fund ( PRF #45353-AC7 ) for support of this work. The authors are pleased to recognize the contributions of Matthew A. Borns to the early stages of this study, and the supporting dielectric experiments completed by Michael K. Abney.
Keywords
- Dielectric spectroscopy
- Dynamic mechanical analysis
- Glass transition
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry