Abstract: Substituted phenyl-benzimidazo compounds are disclosed in which the phenyl group which is attached to the two position of the imidazo ring contains a carboxylic acid group, or derivatives thereof, para to the point of imidazo attachment. The benzimidazo is substituted in the 5,6 positions with amino groups or derivatives thereof. The compounds are particularly useful as AB-monomers in the preparation of poly [(2,6-imidazobenzimidazo)1,4-phenylene].

Abstract: Thermally stable dioxo and dithio-benzisoquinoline polymers are synthesized by the polycondensation of oxyarylene and thioarylene bis-naphthalic acid dianhydrides and aromatic diamino compounds. The compositions are particularly useful in high temperature applications such as in the fabrication of plastics, composites, fibrous materials, protective coatings and films.

Abstract: As new compositions of matter, ethynyl-substituted aromatic ortho-diamines. The compounds are useful as endcapping agents for thermally stable heterocyclic oligomeric compositions.

Abstract: An aromatic bis(o-diamine) is reacted with an aromatic bisbenzil to provide a benzil end-capped quinoxaline oligomer which is then reacted with 4-(3-ethynylphenoxy)orthophenylene diamine to give an ethynyl terminated polyquinoxaline. Because the polyquinoxalines can be cured to provide thermally stable polymer compositions having superior mechanical properties, the compositions are particularly suitable for use in the fabrication of reinforced composite structures.

Abstract: Quinoxaline polymers are synthesized by solution polycondensation of 2,2'-bis(phenylethynyl)-5,5'-diaminobenzidine with aromatic bis-benzils. Upon heating the polymers so prepared at a temperature ranging from about 240.degree. to 300.degree.C, they undergo a thermal intramolecular cyclization reaction, thereby providing cured, thermally stable, highly fused quinoxaline composition. Because of their solubility in aprotic solvents and the mechanism whereby they are cured, the quinoxaline polymers are particularly suitable for use in high temperature applications such as in the fabrication of plastic composites and protective coatings.

Abstract: Tetranitro aryl ether compounds are prepared by aromatic nucleophilic substitution of various aryl diols with 4-fluoro-1,2-dinitrobenzene. By reducing the nitro moieties of the tetranitro compounds, tetraamino aryl ether compounds are obtained. These latter compounds are useful as monomers in preparing thermally stable polymers having good solubility parameters.