Synthesis and characterization of soluble aromatic polyazomethines from 2,5‐bis(4‐aminophenyl)‐3,4‐diphenylthiophene and aromatic dialdehydes

New soluble aromatic polyazomethines with inherent viscosities of 0.4–0.8 dL/g were prepared by the solution polycondensation of 2,5‐bis(4‐aminophenyl)‐3,4‐diphenylthiophene, bis(4‐aminophenyl) ether, and aromatic dialdehydes in o‐chlorophenol at 20°C. The copolyazomethines are generally soluble in chlorinated hydrocarbons, amide‐type or phenolic solvents. The thermal stability of the polymers, which showed no weight loss up to 400°C in both air and nitrogen atmospheres.