Otro
Dielectric relaxation and dc conductivity on the PVOH-CF(3)COONH(4) polymer system
Registro en:
Ionics. Heidelberg: Springer Heidelberg, v. 15, n. 5, p. 537-544, 2009.
0947-7047
10.1007/s11581-009-0320-x
WOS:000269952300003
Autor
Castillo, J.
Chacon, M.
Castillo, R.
Vargas, R. A.
Bueno, Paulo Roberto
Varela, José Arana
Resumen
In the present paper, the ionic conductivity and the dielectric relaxation properties on the poly(vinyl alcohol)-CF(3)COONH(4) polymer system have been investigated by means of impedance spectroscopy measurements over wide ranges of frequencies and temperatures. The electrolyte samples were prepared by solution casting technique. The temperature dependence of the sample's conductivity was modeled by Arrhenius and Vogel-Tammann-Fulcher (VTF) equations. The highest conductivity of the electrolyte of 3.41x10 (-aEuro parts per thousand 3) (Omega cm) (-aEuro parts per thousand 1) was obtained at 423 K. For these polymer system two relaxation processes are revealed in the frequency range and temperature interval of the measurements. One is the glass transition relaxation (alpha-relaxation) of the amorphous region at about 353 K and the other is the relaxation associated with the crystalline region at about 423 K. Dielectric relaxation has been studied using the complex electric modulus formalism. It has been observed that the conductivity relaxation in this polymer system is highly non-exponential. From the electric modulus formalism, it is concluded that the electrical relaxation mechanism is independent of temperature for the two relaxation processes, but is dependent on composition.