Complex permittivity and conductivity of poly(p-phenylenediazomethine) and its blends at microwave frequencies

Abstract

Poly(p-phenylenediazomethine) was synthesized by the condensation reaction between glyoxal and p-phenylene diamine in different solvents like methanol, toluene, m-cresol and N,N-dimethylformamide. The dielectric properties and microwave conductivity of the pelletized samples were measured using cavity perturbation technique. The measurements were done at 2.17 GHz at room temperature (25°C). The effect of dopants on the dielectric properties and conductivity was studied using HCl and HClO₄. Dielectric properties like dielectric constant, dielectric loss factor and microwave conductivity increased on doping with HCl and HClO₄. Conducting polymer composites were prepared by in situ polymerization of glyoxal and p-phenylenediamine in different solvents containing different amounts of PVC, and silica. The microwave conductivity and complex permittivity of each sample was measured. The effect of dopants like HClO₄ and HCl on these dielectric properties was also studied. The d.c. conductivity of the pressed samples measured by the two-probe method was also studied.