Claims
- 1. A method of rendering shaped preceramic polymers infusible prior to pyrolysis, which method comprises treating a shaped preceramic polymer with a plasma of a gas selected from the group consisting of NH.sub.3, N.sub.2, H.sub.2, H.sub.2 O, O.sub.2, BCl.sub.3, diborane, silanes, boranes, methylamine, hydrazine, and methane for a time sufficient to render the preceramic polymer infusible wherein the treatment temperature is sufficiently low so that the preceramic polymer remains unfused during the treatment step.
- 2. A method as claimed in claim 1 wherein the shaped preceramic polymer is a fiber.
- 3. A method as claimed in claim 1 wherein the plasma is ammonia gas.
- 4. A method as claimed in claim 1 wherein the plasma is methane gas.
- 5. A method as claimed in claim 1 wherein the plasma is nitrogen.
- 6. A method as claimed in claim 1 wherein the plasma is hydrogen gas.
- 7. A method as claimed in claim 1 wherein the plasma is water.
- 8. A method as claimed in claim 1 wherein the plasma is oxygen.
- 9. A method as claimed in claim 1 wherein the plasma is a silane.
- 10. A method as claimed in claim 1 wherein the plasma is a borane.
- 11. A method as claimed in claim 1 wherein the preceramic polymer is exposed to the plasma for a period of at least 5 minutes and for no more than three hours.
- 12. A method as claimed in claim 1 wherein the treatment with the plasma is carried out under pressure in the range of 0.05 torr to 5 torr.
- 13. A method as claimed in claim 1 wherein the treatment with the plasma is carried out under a gas flow of 0.01 cc/minute to 10 cc/minute.
- 14. A method as claimed in claim 1 wherein the preceramic polymer is a polysilazane preceramic polymer.
- 15. A method as claimed in claim 1 wherein the preceramic polymer is a polycarbosilane preceramic polymer.
- 16. A method as claimed in claim 1 wherein the preceramic polymer is a methylpolysilane preceramic polymer.
- 17. A method as claimed in claim 1 wherein the shaped preceramic polymer is a powder.
- 18. A method as claimed in claim 1 wherein the shaped preceramic polymer is a foam.
- 19. A method as claimed in claim 1 wherein the shaped preceramic polymer is a film.
Government Interests
The Government has rights in this invention pursuant to Contract No. F33615-83-C-5006 awarded by the United States Air Force.
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4568563 |
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Feb 1986 |
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Foreign Referenced Citations (1)
Number |
Date |
Country |
2583744 |
Dec 1986 |
FRX |