Synthesis and characterization of new soluble thermally stable poly(azomethine-etherimide)s: discerning the possibility for high temperature applications

A new series of polyimides was synthesized by the condensation of monomers (azomethine-ether diamine, DA-1 and DA-2) with pyromelliticdianhydride (PMDA), 3,4,9,10-perylenetetracarboxylic dianhydride (PD) and 3,3'4,4'-benzophenonetetracarboxylic dianhydride (BD). The structural explications of monomers and polyimides was conducted by FT-IR, H-1 NMR and elemental analysis. All polyimides were found soluble in polar aprotic solvents and found to be semicrystalline in nature confirmed by XRD. The inherent viscosities were found in the range of 0.67-0.77 g/dl. %. Average molecular weight (MW) and number average molecular weight (Mn) of the polyimides were found in the range of 5.72 x 10(5) g/mol-6.58 x 10(5) g/mol and 3.79 x 10(5) g/mol 4.11 x 10(5) g/mol respectively. The polyimides exhibited excellent thermal properties having a glass transition temperature T-g in the range of 230-290 degrees C and the 10% weight loss temperature was above 450 degrees C. The values of thermodynamic parameters, activation energy, enthalpy and entropy fall in the range of 45.2-53.90 kJ/mol, 43.5-52.30 kJ/mol and 0.217 kJ/mol k to 0.261 kJ/mol k respectively. Copyright (C) 2015 John Wiley & Sons, Ltd.