Solution-cast blends of polyaniline-DBSA with EVA copolymers

Conducting blends of ethylene-vinyl acetate (EVA) copolymers with different vinyl acetate content and polyaniline doped with dodecylbenzenesulfonic acid (Pani-DBSA) prepared by three different procedures were prepared by solution-cast process. Blend films with EVA 18 (with 18 wt.% of VA) presented gross-phase separation, resulting in a formation of Pani-enriched (glass-contacted film surface) and Pani-deficient (air-exposed film surface) layers. The use of EVA41 (with 41 wt.% of VA) resulted in blends with homogeneous conductivity (similar conductivity in both sides of the film). Better electrical performance was achieved in blends with Pani-DBSA produced by a redoping process. Concerning Pani-DBSA prepared by one-step polymerization, one prepared by inverted emulsion polymerization, resulted in EVA41-based blends with lower percolation threshold point and a more homogeneous morphology than that prepared with Pani-DBSA from aqueous dispersion polymerization. (C) 2002 Elsevier Science B.V. All rights reserved.