Blends of poly(vinylidene fluoride) and polyaniline derivatives

Summary form only given. Blends of poly(o-alkoxyanilines) and poly(vinylidene fluoride) - PVDF - of various compositions were prepared from organic solvent solutions. Because these polyaniline derivatives present high solubility, they could be doped (with e.g. trifluoroacetic acid) under different conditions: i) before polymer dissolution; ii) after dissolving the polymer and mixing the blend; iii) even after films being formed. Flexible, free-standing and stretchable films were obtained by casting, which were characterized by conductivity and dielectric polarization measurements, X-ray diffraction and cyclic voltammetry. As expected, the blends conductivity increases with increasing concentration of the conducting polymer. The onset of the conductivity at low conducting polymer contents indicates a low percolation threshold for these blends. The electrochemical response shows the blends to be electroactive and present electrochromic properties similar to the pure polyalkoxyanilines. Also, blends with interesting insulating behavior, such as dielectric polarization and the presence of the piezoelectric /spl beta/-phase of PVDF, could be obtained by selecting appropriate preparation conditions or by zone drawing the films.