Dielectric absorption in oriented poly(vinylidene fluoride)
β Scribed by Kakutani, Haruko
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1970
- Tongue
- English
- Weight
- 367 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0449-2978
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β¦ Synopsis
Abstract
The dielectric behavior of poly(vinylidene fluoride) is affected by orientation and crystal modification. The loss peak caused by molecular motion of the molecules in crystalline regions appears at about 70Β°C (110 Hz) (Ξ±~1~ absorption) for the Ξ± form, and at about 110Β°C (110 Hz) (Ξ±~2~ absorption) for the Ξ² form. Orientation significantly affects the magnitude of the Ξ² absorption which appears at about β40Β°C. The very high value of the dielectric constant for stretched film is believed to be due to the orientation effect. The Ξ³ absorption, which is assumed to be localβmode absorption, is not so much affected by orientation. An additional loss peak has been found at around 0Β°C in dynamic mechanical measurements, but the molecular mechanism is unknown.
π SIMILAR VOLUMES
## Abstract The dielectric properties of poly(vinylidene fluoride) have been studied in the frequency range 10 Hz to 100 kHz at temperatures between β196 and 150Β°C. Three dielectric relaxations were observed: the Ξ± relaxation occurred near 130Β°C, the Ξ² near 0Β°C, and the Ξ³ near β30Β°C at 100 kHz. In