New sulfur-containing aromatic diamines and related soluble polyimides

New aromatic diamines containing thiophenyl and phenylsulfonyl substituents were synthesized by aromatic nucleophilic substitution of a nitro group in 1,3,5-trinitrobenzene (the product of 2,4,6-trinitrotoluene demethylation) by thiophene, followed by transformation of the reaction product. The reaction of these diamines with aromatic tetracarboxylic dianhydrides yielded new sulfur-containing polyimides soluble in organic solvents.