Synthesis and properties of organosoluble and thermal stable polyimides from 3,5-diamino-N-(4-(5-(4,5-diphenyl-1H-imidazol-2-yl)furan-2-yl)phenyl)benzamide

In this investigation, a novel aromatic diamine containing imidazole, furan and benzamide units in the side chain was successfully synthesized via direct condensation of 2-[5-(4-aminophenyl)furan-2-yl]-4,5-diphenyl-1H-imidazole with 3,5-dinitrobenzoyl chloride and following reduction in the dinitro compound. A series of novel polyimides (PI)s with aromatic heterocyclic structure were synthesized by a conventional two-step polymerization process from the reaction of aromatic diamine monomer with tetracarboxylic dianhydrides. These polymers were characterized using Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (¹H NMR), X-ray diffraction (XRD) and elemental and thermogravimetric analysis techniques. The resulting PIs exhibited good thermal stability and small mass loss before temperature of 400 °C in nitrogen. They showed high solubility in polar organic solvents, such as NMP, DMAc, DMSO and DMF at room temperature. XRD studies exhibited that the obtained polymers exhibit amorphous morphology. In this research, PIs were used as a novel and efficient adsorbent for removal of malachite green dye from aqueous solution. The results showed that prepared PIs are an effective adsorbent for the removal of Cu ions from aqueous solutions.