Relaxation behavior of methacrylic polymers with bulky hydrophilic groups in their structures
✍ Scribed by Vicente Compañ; Julio Guzmán; Ricardo Díaz-Calleja; Evaristo Riande
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 226 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0887-6266
No coin nor oath required. For personal study only.
✦ Synopsis
The isochrones showing the temperature dependence of the loss relaxation modulus of poly(neopentyl glycol methacrylate) present an ostensible subglass absorption called  relaxation that roughly has the same intensity as the glass-rubber relaxation, or ␣ process. The dielectric relaxation spectrum of this polymer also exhibits a well-developed  process followed at higher temperatures by the glass-rubber, or ␣ relaxation, which strong conductive effects only permit to be detected at high frequencies. A detailed study of the conductive contributions to the dielectric loss above T g was carried out using a theory that assumes that the dispersion observed in tan ␦ in the frequency domain arises from the Maxwell-Wagner-Sillars effect combined with Nernst-Planck electrodynamic effects caused by interfacial polarizations in the interface polymer electrodes. Attempts were made to evaluate the equivalent salt concentration that would produce the conductive effects experimentally observed.