Polymers containing anthraquinone units: Polymers from 1,5-diaminoanthraquinone and aralkyldiketones

Schiff's-base polymers have been formed by the condensation of 1,5-diaminoanthraquinone with 1,4- and 1,3-diacetylbenzene and 2,6-diacetylpyridine. These polymers were soluble in methanesulfonic and concentrated sulfuric acids (1,4-diacetylbenzene polymer) or N,N-dimethylacetamide. The polymer formed from 1,4-diacetylbenzene was ring-closed in polyphosphoric acid to yield a thermally stable polymer soluble in concentrated sulfuric acid which lost only 10% of its weight at 900°C in a TGA test.