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| Titel: |
Dielectric Relaxation and Electrical Conductivity Study in Thiourea- Doped Poly (Vinyl Alcohol) |
| Auteur: |
Fahmy, T. |
| Verschenen in: |
International journal of polymeric materials |
| Paginering: | Jaargang 50 (2001) nr. 1 pagina's 109-127 |
| Jaar: |
2001-07-01 |
| Inhoud: |
FT-IR, UV-spectroscopy and X-ray diffraction of thiourea-Poly (vinyl alcohol) (PVA) complexes have been investigated. It was observed that thiourea affected the structure of PVA. X-ray study revealed that as the thiourea salt increases the crystallinity of PVA increases. The dielectric properties of thiourea-PVA complexes were investigated in the frequency range 0.2 to 100 kHz and the temperature range 293 to 433 K. All samples are characterized by high values of dielectric permittivity at low frequencies and high temperatures. The results are discussed in terms of interfacial Maxwell-Wagner-Sillars (MWS) polarization and space-charge polarization. Different relaxation modes, i.e., β and α-relaxations have been observed in pure PVA. AC conductivity measurements of samples showed that the hopping conduction mechanism dominates at low temperature region, from room temperature to the glass transition temperature. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 5 van 10 gevonden artikelen
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