Curable, thermally stable poly(enaminonitriles)

Three new bis(1-chloro-2,2-dicyanovinyl) aromatic monomers have been synthesized. Vinylic nucleophilic substitution polymerization with 4,4'-diaminodiphenyl ether led to moderately high molecular weight poly(enaminonitriles) (0.39 < ( eta ) < 0.84 dL/g, measured in dimethylformamide at 25 deg C). The polymers exhibited excellent thermal stability, retaining 100% of their mass up to 400 deg C under nitrogen. Evidence is presented for an intramolecular cyclization reaction occurring > 300 deg C to form poly(4-aminoquinoline) repeat units. The cyclization reaction occurs without the emission of volatile byproducts, which is a drawback in the curing of polyimides. The dielectric constant of a representative polymer of this class was found to be approximately eight before heat treatment and five afterward. 21 ref.--AA