Document Type: Research Article
Department of Chemistry, Mashhad Branch, Islamic Azad University, Mashhad, I.R. Iran
Department of Chemistry, Bojnourd Branch, Islamic Azad University, Bojnourd, I.R. Iran
A new aromatic diamine monomer containing ether linkage based on the phenanthrimidazole ring, 1,1´-(4,4´- oxy bis(1,4-phenylene))bis(2-(4-aminophenyl)-1H-phenanthro[9,10-d]imidazole) was synthesized through four-components condensation of 4,4´-diamino diphenyl ether, 4-nitrobenzaldehyde, phenanthrene-9,10-dione and ammonium acetate in presence of acetic acid, followed by palladium-catalyzed hydrazine monohydrate reduction. This new monomer was further confirmed by FT-IR, 1H NMR, and 13C NMR spectroscopy. A series of new aromatic polyamides containing phenanthrimidazole ring in the main chain was prepared by direct polycondensation of the prepared diamine with four commercially available aromatic and aliphatic diacids. These polymers are essentially amorphous and were soluble in polar aprotic solvents such as DMF, NMP, DMAc, and DMSO. Inherent viscosities of polyamides were in the range 0.42–0.53 dL/g indicating the formation of medium molecular weight polymers. Polyamides exhibited glass-transition temperature (Tg) in the range 260-280 °C. The 10% weight loss temperature in air atmosphere measured by TGA was in the range 454-526 °C indicating their good thermal stabilities. The photophysical properties of diamine and polyamides were investigated by UV-Vsible and fluorescence spectroscopy.