Abstract
New aromatic polyazomethines were synthesized from two tetraphenylated heterocyclic diamines, 3,4-bis(4-aminophenyl)-2,5-diphenylpyrrole (DATPP), and 3,4-bis(4-aminophenyl)-2,5-diphenylthiophene (DATPT) with two aromatic dialdehydes, isophthalaldehyde (IPA), and terephthalaldehyde (TPA) by solution polycondensation in o-chlorophenol at room temperature. In addition, DATPP-based copolyazomethines were prepared by reacting the diamine with a combination of IPA and TPA. These polymers had inherent viscosities in the range of 0.32~0.62 dL/g and showed amorphous patterns in X-ray diffraction studies. The polyazomethines derived from IPA and the copolyazomethines with TPA containing less than 50 mol% were fairly soluble in various organic solvents such as N-methyl-2-pyrrolidone, o-chlorophenol, and 1,1,2,2-tetrachloroethane. In thermogravimetric analysis (TGA), all the polymers did not lose weight below 41$0^{\circ}C$ in air and nitrogen, and their 5% weight loss temperature in air and nitrogen were in the range of 445~485$^{\circ}C$ and 490~52$0^{\circ}C$, respectively. Differential scanning calorimetry curves also revealed decomposition behaviors similar to those observed in TGA analysis with no transition below the decomposition temperatures.