Synthesis and characterization of organosoluble polyamides from quinoxaline based diamine

Aromatic/aliphatic polyamides were synthesized from a diamine monomer, 2,3-bis-p-aminophenylquinoxaline (IV), based on quinoxaline and various dicarboxylic acids of aliphatic, aromatic and heterocyclic. The diamine and polyamides were characterized by elemental analysis, FTIR and 1H-NMR. The solubility of the polyamides was affected by the quinoxaline and heterocyclic groups in the polymer chain. They were all soluble in common organic solvents such as dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF) and N-methylpyrolidone (NMP). The polyamides showed inherent viscosity in the range of 0.25–0.3 dL/g in DMSO at 25°C and good thermal stability with the char yields in the range of 65%–82% at 600°C in nitrogen.