Abstract: Provided herein are phthalonitrile adhesive formulations and methods of making and using the adhesive formulations. An illustrative adhesive formulation comprises a phthalonitrile additive selected from a group consisting of 1,2-dicyanobenzene; a derivative of 1,2-dicyanobenzene; and combinations thereof; a bisphthalonitrile compound; and a curing agent; wherein the phthalonitrile additive does not comprise an ether functional group and does not comprise a thioether functional group.

Abstract: Provided herein are phthalonitrile adhesive formulations and methods of making and using the adhesive formulations. An illustrative adhesive formulation comprises a phthalonitrile additive selected from a group consisting of 1,2-dicyanobenzene; a derivative of 1,2-dicyanobenzene; and combinations thereof; a bisphthalonitrile compound; and a curing agent; wherein the phthalonitrile additive does not comprise an ether functional group and does not comprise a thioether functional group.

Abstract: A method for repairing a high temperature composite structure fabricated from layers of composite plies. If the composite structure contains an internal high temperature core, the core is first restored by installing a core block into the damaged region, bonding the core block in place by applying high temperature material resin and uncured foam material into the region between the core block and the damaged region, and partially curing the core block. A number of repair plies, formed from pre-impregnated composite material or formed using dry cloth manually impregnated with high temperature resin are prepared. The repair plies are sized and shaped using a series of templates corresponding to the damaged region. The installed plies are cured using high temperature localized heating of the damaged region without impairing the surrounding structure.

Abstract: A syntactic foam-core material and method for its production are disclosed wherein glass microspheres and chopped fiberglass are dispersed within a slurry comprised of a suitable resin such as an epoxy and a suitable solvent such as methyl ethyl ketone. Under carefully controlled vacuum and rate of addition conditions, the microspheres and chopped fiberglass are added to the slurry to form a light weight syntactic foam-core material. The material may either be stored under cold conditions for use at a later time as a B-stage material or it may be shaped and/or molded to conform to a desired configuration which, for example, may correspond with a desired component part. After curing, the material may be machined to final dimensions. The material may be characterized as a tightly packed network of resin-coated microspheres spaced by controlled, yet random voids comprising at least 20%, and more usually, between 23 and 25% by volume, of the fully-cured material.

Abstract: A syntactic foam-core material and method for its production are disclosed wherein glass microspheres and chopped fiberglass are dispersed within a slurry comprised of a suitable resin such as an epoxy and a suitable solvent such as methyl ethyl ketone. Under carefully controlled vacuum and rate of addition conditions, the microspheres and chopped fiberglass are added to the slurry to form a light weight syntactic foam-core material. The material may either be stored under cold conditions for use at a later time or it may be shaped and/or molded to conform to a desired configuration which, for example, may correspond with a desired component part. After curing, the material may be machined to final dimensions.