| Abstract: | Infrared and optical spectra, differential thermal analysis, dc electrical resistivity, magnetic susceptibility, electron spin resonance, and microwave response of CuCl2‐filled poly(vinylidene fluoride) (PVDF) films, over the filler mass fraction range 0.05 ≤ W ≤ 0.4, were measured. The infrared spectra evidenced the presence of β‐phase, for all of the filler levels with main deformations of 20% (for W = 0.25) and 30% (for other filler levels) head‐to‐head and tail‐to‐tail units, which were considered as polaron and bipolaron defects. Optical activity was mainly influenced by PVDF structure. Differential thermal analysis revealed dipole relaxation and premelting endothermic peaks. A quasi–one‐dimensional interpolaron hopping was thought to proceed in the direct current electric conduction, with a hopping distance less than the distance between two successive head‐to‐head sites. A temperature‐independent Pauli paramagnetic behavior was observed, confirming the presence of induced energy bands due to CuCl2 filling. Most of the observed electron spin resonance signals were antisymmetric, with superimposed repels due to the hyperfine interactions characterizing PVDF. The obtained linear dependence of the isotropic hyperfine coupling constant (ΔA` ), for Cu(II), on average g‐factor, implied that ΔA` is a measure of the valence electron spin polarization. An octahedral or distorted octahedral configuration was suggested for Cu(II). The present system is a good microwave modulator. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 771–781, 1999 |
