The molecular relaxation characteristics of rubbery amorphous crosslinked networks based on poly(ethylene glycol) diacrylate [PEGDA] and poly(propylene glycol) diacrylate [PPGDA] have been investigated using broadband dielectric spectroscopy. Dielectric spectra measured across the sub-glass transition region indicate the emergence of an intermediate "fast" relaxation in the highly crosslinked networks that appears to correspond to a subset of segmental motions that are more local and less cooperative as compared to those associated with the glass transition. This process, which is similar to a distinct sub-Tg relaxation detected in poly(ethylene oxide) [PEO], may be a general feature in systems with a sufficient level of chemical or physical constraint, as it is observed in the crosslinked networks, crystalline PEO, and PEO-based nanocomposites.
|Number of pages||11|
|State||Published - Jan 12 2007|
Bibliographical noteFunding Information:
We are pleased to acknowledge support from the Kentucky Science and Engineering Foundation as per Grant Agreement KSEF-148-502-05-130 with the Kentucky Science and Technology Corporation. This study was also supported through a Major Research Equipment Grant awarded by the Office of the Vice President for Research at the University of Kentucky.
Activities at the University of Texas were supported in part by the Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy (Grant no. DE-FG02-02ER15362). However, any opinions, findings, conclusions, or recommendations expressed herein are those of the authors and do not necessarily reflect the views of the DOE. Partial support from the National Science Foundation under grant number CTS-0515425 is also acknowledged.
- Dielectric spectroscopy
- Poly(ethylene oxide)
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry