Synthesis, characterization and electrochemical properties of poly(phenoxy-imine)s containing carbazole unit

Abstract

Several new Schiff base polymers were synthesized via oxidative polymerization method in an aqueous alkaline medium in the presence of NaOCl as an oxidant and were confirmed by FT-IR, 1H-NMR, 13C-NMR and UV–Vis spectroscopic techniques. Furthermore, cyclic voltammetry measurements were carried out and the HOMO–LUMO energy levels and electrochemical band gaps (Eg′) were calculated. Additionally, the optical band gaps (Eg) were determined using their UV–Vis spectra of the materials. The morphologic properties of the polymers were investigated by scanning electron microscopy. In addition, the number average molecular weight (Mn), weight average molecular weight (Mw) and polydispersity index values of the polymers were determined by gel permeation chromatography technique. Electrical conductivity measurements of the doped (with iodine) and undoped polymer related to doping time were carried out by four-point probe technique using a Keithley 2400 electrometer. Their thermal behaviors were determined by TG–DTA and DSC measurements. The synthesized compounds were soluble in common solvents such as DMF, THF and DMSO. Photoluminescence properties of the polymers were determined in different concentrations of DMF solvent.