Dielectric, FTIR spectroscopic and atomic force microscopic studies on polypyrrole-poly(acrylonitrile-co-vinyl acetate) composites

In this study, Poly(acrylonitrile-co-vinyl acetate) [P(AN-co-VAc)] composite films were fabricated by chemical polymerization of pyrrole (Py) with cerium(IV) (Ce(IV)) on P(AN-co-VAc) matrix. The effect of amount of Py and temperature on the composite film properties was studied in a frequency range starting from 0.05 Hz to 10 MHz and in a temperature range from 0 to 250°C. The electric modulus provides a good description of the dielectric relaxation of the conducting polymer composites. The atomic force microscopy images of the polypyrrole (PPy)-P(AN-co-VAc) composites show the polymerization of Py on P(AN-co-VAc) matrix producing different sized grainy orientations resulting in higher conductivity values that increase with average grain size. The real [(ε′) or ε′(ω)] and imaginary [(ε″) or ε″(ω)] parts of the permittivity of PPy-P(AN-co-VAc) composite were comparatively higher than PPy-Polyacrylonitrile (PAN) and P(AN-co-VAc). It was also seen that the conductivity of PPy-P(AN-co-VAc) composite was considerably higher than PPy-PAN and P(AN-co-VAc) itself.