Abstract: A polymerizable composition suitable for storage prior to polymerization is made by mixing a phthalonitrile monomer and a curing agent under non-reactive conditions below the melting temperatures of the phthalonitrile monomer and the curing agent and in the absence of a solvent to create a homogeneous, unreacted mixture.

Abstract: A fiber-reinforced phthalonitrile composite is made by impregnating or coating a fibrous material with a phthalonitrile prepolymer mixture containing a phthalonitrile monomer and an aromatic amine curing agent that is thermally stable and nonvolatile at a temperature up to about 375.degree. C., and that contains at least one electron withdrawing substituent effective to reduce the reactivity of the aromatic amine curing agent with the phthalonitrile monomer.

Abstract: A carbon-based composite is made by the steps of(1) impregnating a fibrous material with a phthalonitrile thermoset polymer precursor,(2) curing the product of step (1) to form a fiber-reinforced thermoset polymer and(3) pyrolyzing the product of step (2) to form the carbon-based composite. The carbon-based composite may be made with only one cycle of the steps (1), (2), and (3).

Abstract: Phthalonitrile thermoset polymers and composites having flame resistance formed by combining a phthalonitrile monomer in the melt stage with a halogen-containing aromatic amine curing agent. The halogen-containing aromatic amine curing agent is selected from the group consisting of aromatic amine curing agents having the general formula:NH.sub.2 --(Ar.sup.2 O--).sub.y Ar.sup.1 --X--Ar.sup.1 (--OAr.sup.2).sub.y --NH.sub.2wherein Ar.sup.1 and Ar.sup.2 are substituted or unsubstituted aromatic groups, y is 0 or greater, and X is --C(CF.sub.3).sub.2 -- and aromatic amine curing agents having the general formula:NH.sub.2 --(Ar.sup.4 O--).sub.u Ar.sup.3 --Z--Ar.sup.3 (--OAr.sup.4).sub.u --NH.sub.2wherein Z is a connecting bond or a linking group other than oxygen or --C(CF.sub.3).sub.2 --, u is 0 or greater, and Ar.sup.3 and Ar.sup.4 are aromatic groups and wherein either Ar.sup.3 or Ar.sup.1 or both Ar.sup.3 and Ar.sup.4 are substituted with at least one halogen atom or halo-substituted alkyl group.

Abstract: A fiber-reinforced phthalonitrile composite is made by impregnating or coating a fibrous material with a phthalonitrile prepolymer mixture containing a phthalonitrile monomer and an aromatic amine curing agent that is thermally stable and nonvolatile at a temperature up to about 375.degree. C., and that contains at least one electron withdrawing substituent effective to reduce the reactivity of the aromatic amine curing agent with the phthalonitrile monomer.

Abstract: Metal foams are impregnated with a phthalonitrile prepolymer. The metal f/polymer composite formed upon curing has excellent acoustic damping, structural properties, oxidative stability, and flame resistance. Foams of various metals, such as aluminum, titanium, nickel, copper, iron, zinc, lead, silver, gold, platinum, tantalum, and alloys based on these metals may be used.