Synthesis of soluble and thermally stable polyimide from new diamine bearing N-[4-(9H-carbazol-9-yl)phenyl] formamide pendent group

A new aromatic diamine monomer. N-(4-(9H-carbazol-9-yl)phenyl)-3,5-diaminobenzamide, was successfully prepared in four steps using carbazole as starting material and polymerized with three aromatic tetraicaboxylic acid dianhydrides via the conventional two-stage synthesis including the polyaddition and chemical cyclodehydration to produce a series of the aromatic polyimides. The polyimides were characterized by FT-IR, H-1 NMR, and C-13 NMR spectroscopy, differential scanning calorimetric (DSC) and thermo gravimetric analysis (TGA) analysis. The polyimides with inherent viscosities in the range of 0.38-0.46 dL/g showed excellent solubility in various solvents such as N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), pyridine and dioxane. DSC showed the glass transition temperatures (T-g) in the range of 277-288 degrees C. TGA showed that all polymers were stable, with 10% weights loss recorded above 524 degrees C in air atmosphere. Preliminary tests on films of the polyimides indicate that the materials are brittle. (C) 2009 Elsevier Ltd. All rights reserved.