Abstract: Disclosed herein are methods of curing silicon carbide precursor polymer fibers such as polysilazanes using moisture and free radical generators such as peroxides. Also disclosed are methods of forming curing and using silicon carbide precursor polymers that contain alkenyl groups and free radical generators such as peroxides.
WE CLAIM
1. A method of curing a polysilazane fiber comprising:
a) forming a polysilazane fiber by:
i. reacting at least one methylchlorodisilane; at least one organochlorosilane comprising at least one alkenyl group; and at least one nitrogen-containing additive to form a resin;
ii. combining the resin with at least one free-radical generator and optionally at least one inhibitor to form a resin mixture; and
iii. spinning said resin mixture to form said polysilazane fiber, wherein said spinning is performed at a temperature below the 1 hr. half-life temperature of the free radical generator;
b) exposing said polysilazane fiber to moisture; and
c) curing said polysilazane fiber by exposing said polysilazane fiber to a temperature above the 1 hr half-life temperature of the free radical generator but below the softening point temperature of the moisture-exposed polysilazane fiber.
2. The method according to claim 1, wherein said free radical generator is selected from a peroxide, a peroxycarbonate, a peroxysiloxane, and an azo-containing compound.
3. The method according to claim 2, wherein said free radical generator is a peroxide.
4. The method according to claim 1, wherein said at least one alkenyl group is selected from vinyl, allyl, acrylate, methacrylate, vinylether, or styryl.
5. The method according to claim 4, wherein said at least one alkenyl group is vinyl.
6. The method according to claim 1, wherein said organochlorosilane is of formula
wherein
Ra is selected from hydrogen, (Ci-Ci2)alkyl, phenyl, vinyl, allyl, acrylate, and methylacrylate, or a combination thereof; and
Rb is selected from chlorine, hydrogen, (Ci-Ci2)alkyl, phenyl, vinyl, allyl, acrylate, and methylacrylate, or a combination thereof.
7. The method according to claim 6, wherein Ra is selected from (Ci-C^alkyl, phenyl, vinyl, allyl, acrylate, methylacrylate, and vinylbenzyl.
8. The method according to claim 6, wherein Rb is selected from chlorine, (Ci-C4)alkyl, phenyl, vinyl, allyl, acrylate, methylacrylate, and vinylbenzyl.
9. The method according to claim 1, wherein said exposing said polysilazane fiber to moisture is performed at a temperature between 20°C and 250°C.
10. The method according to claim 1, wherein said curing of said polysilazane fiber occurs at a temperature between 160°C and 200°C.
11. The method according to claim 1, wherein said polysilazane fiber is a polydisilazane fiber.
12. A method of curing a polysilazane fiber, comprising:
a) exposing a polysilazane fiber comprising at least one alkenyl group and
a free radical generator to moisture; and
b) curing said polysilazane fiber by exposing said polysilazane fiber to a
temperature above the 1 hr half-life temperature of the free radical
generator but below the softening point temperature of the moisture-
exposed polysilazane fiber.
13. The method according to claim 12, wherein said free radical generator is selected from a peroxide, a peroxycarbonate, a peroxysiloxane, and an azo-containing compound.
14. The method according to claim 13, wherein said free radical generator is a peroxide.
15. The method according to claim 12, wherein said at least one alkenyl group is selected from vinyl, allyl, acrylate, methacrylate, vinylether, or styryl.
16. The method according to claim 15, wherein said at least one alkenyl group is vinyl.
17. The method according to claim 12, wherein said exposing said polysilazane fiber to moisture is performed at a temperature between 20°C and 250°C.
18. The method according to claim 12, wherein said curing of said polysilazane fiber occurs at a temperature between 160°C and 200°C.
19. A method of preparing a silicon carbide fiber, comprising:
a) forming a polydisilazane resin comprising reacting at least one methylchlorodisilane; at least one organochlorosilane comprising at least one alkenyl group; and at least one nitrogen-containing additive to form a resin;
b) combining the resin with at least one free-radical generator and optionally at least one inhibitor to form a resin mixture;
c) spinning said resin mixture to form a polysilazane fiber, wherein said spinning is performed at a temperature below the 1 hr half-life temperature of the free radical generator;
d) exposing said polysilazane fiber to moisture;
e) curing said polysilazane fiber by exposing said polysilazane fiber to a
temperature above the 1 hr half-life temperature of the free radical but
below the softening point temperature of the moisture-exposed polysilazane fiber to form a cured polysilazane fiber; and
f) heating said cured polysilazane fiber.
20. The method according to claim 12, wherein said polysilazane fiber is a polydisilazane fiber.
| # | Name | Date |
|---|---|---|
| 1 | PROOF OF RIGHT [22-08-2016(online)].pdf | 2016-08-22 |
| 2 | Priority Document [22-08-2016(online)].pdf | 2016-08-22 |
| 3 | Power of Attorney [22-08-2016(online)].pdf | 2016-08-22 |
| 4 | Form 5 [22-08-2016(online)].pdf | 2016-08-22 |
| 5 | Form 3 [22-08-2016(online)].pdf | 2016-08-22 |
| 6 | Drawing [22-08-2016(online)].pdf | 2016-08-22 |
| 7 | Description(Complete) [22-08-2016(online)].pdf | 2016-08-22 |
| 8 | 201647028433.pdf | 2016-09-17 |
| 9 | 201647028433-Power of Attorney-240816.pdf | 2016-09-23 |
| 10 | 201647028433-Notarized Assignment-240816.pdf | 2016-09-23 |
| 11 | 201647028433-Correspondence-Notarized Assignment-240816.pdf | 2016-09-23 |
| 12 | abstract-201647028433-jpeg.jpg | 2016-09-28 |
| 13 | 201647028433-FORM 18 [05-02-2018(online)].pdf | 2018-02-05 |
| 14 | 201647028433-RELEVANT DOCUMENTS [27-02-2019(online)].pdf | 2019-02-27 |
| 15 | 201647028433-FORM 13 [27-02-2019(online)].pdf | 2019-02-27 |
| 16 | 201647028433-FORM-26 [06-03-2019(online)].pdf | 2019-03-06 |
| 17 | Correspondence by Agent_Form26_08-03-2019.pdf | 2019-03-08 |
| 18 | 201647028433-FER.pdf | 2019-04-25 |
| 19 | 201647028433-AbandonedLetter.pdf | 2019-11-04 |
| 1 | 201647028433searchreport_24-04-2019.pdf |