Claims
- 1. A lightweight flame resistant composite structure comprising a fire-resistant cellular honeycomb core, having adhered to at least one of its faces a facesheet comprising a reinforced cured vinyl styrylpyridine-bismaleimide copolymer.
- 2. The composite structure of claim 1 wherein only one facesheet is adhered to only one face of the core.
- 3. The composite structure of claim 1 wherein facesheets are adhered to both faces of the core.
- 4. The composite structure of claim 1 wherein the reinforcement in said facesheet is selected from carbon fiber, boron nitride fiber, glass fiber and aramide fiber.
- 5. The composite structure of claim 1 wherein the material of said cellular honeycomb comprises a member of the group consisting of aluminum, aromatic polyamide paper, polyimide dipped aromatic polyamide paper and bismaleimide-fiberglass.
- 6. The composite structure of claim 1 wherein said cured vinyl styrylpyridine-bismaleimide copolymer comprises 10 to 1 parts by weight of bismaleimide copolymerized with one part by weight of a vinyl styrylpyridine oligomer of the structure ##STR8## wherein in the A aromatic rings R.sub.1 is hydrogen or a lower alkyl and the two olefin bonds are attached to the aromatic ring meta or para to one another, and in the B aromatic ring R.sub.2 is a lower alkyl, haloalkyl, or alkoxyl and the two olefin bonds are attached to the B aromatic ring in the 2,6 or 2,4 positions, with R.sub.2 in the 4 or 6 position not occupied by an olefin bond.
- 7. The composite structure of claim 6 wherein R.sub.1 is hydrogen and R.sub.2 is selected from methyl and methoxy.
- 8. The composite structure of claim 7 wherein the reinforcement is selected from carbon fiber, aramide fiber, boron nitride fiber and glass fiber.
- 9. The composite structure of claim 8 wherein the weight ratio of bismaleimide to vinyl styrylpyridine oligomer is from about 5:1 to about 1.5:1.
- 10. The composite structure of claim 6 wherein said facesheet additionally comprises an adhered decorative overlayer.
- 11. The composite structure of claim 10 wherein the reinforcement is selected from carbon fiber, aramide fiber, boron nitride fiber and glass fiber.
- 12. The composite structure of claim 10 wherein said decorative overlayer comprises polyether etherketone.
- 13. A lightweight flame resistant composite structure comprising an aromatic polyamide honeycomb core having adhered to each of its faces a facesheet comprising a cured reinforced vinyl styrylpyridinebismaleimide copolymer comprises 10 to 1 parts by weight of bismaleimide copolymerized with one part by weight of a vinyl styrylpyridine oligomer of the structure ##STR9## wherein in the A aromatic rings R.sub.1 is hydrogen or a lower alkyl and the two olefin bonds are attached to the aromatic ring meta and para to one another, and in the B aromatic ring R.sub.2 is a lower alkyl, haloalkyl, or alkoxyl and the two olefin bonds ae attached to the B aromatic ring in the 2,6 or 2,4 positions, with R.sub.2 in the 4 or 6 position not occupied by an olefin bond reinforced with carbon fibers and adhered to the outside of at least one of said facesheets a polyether ether ketone decorative oversheet.
- 14. The structure of claim 13 wherein the facesheets are adhered to the core with a polymerizable polyimide adhesive.
- 15. The structure of claim 13 wherein the facesheets are adhered to the core with vinyl styrylpyridine-bismaleimide copolymer.
- 16. The structure of claim 13 wherein the vinyl styrylpyridine-bismaleimide copolymer additionally comprises from about 5% to about 20% by weight of an aromatic epoxy modifier.
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Public Law 96-517 (35 U.S.C. .sctn.200 et seq.). The contractor has not elected to retain title to the invention.
US Referenced Citations (11)