High temperature stable conjugated polyazomethines containing naphthalene moiety: Synthesis, characterization, optical, electrical and thermal properties.

A series of azomethine diol monomers containing naphthalene moiety were synthesized and oxidatively polymerized in aqueous alkaline medium using NaOCl as oxidant. The structure of the monomers and polymers was characterized by using various spectroscopic techniques. PL spectra of polymers are exhibiting good emission with high Stokes shift values than the monomers due to their polyconjugated structure. The electrical conductivity of polymers was measured by a two-point probe technique, and it increases with an increase in iodine vapour contact time up to 144 h. The electrical conductivity values were correlated with the charge density on azomethine nitrogen obtained from the Hückel calculation method. The dielectric properties of polymers were studied at different temperatures in the frequency range from 50 Hz to 5 MHz. The synthesized polyazomethines have recorded high thermal stability and are shown by carbon residue of around 50% at 800 °C in the thermogravimetric analysis.