Polybenzoxazine resins with high hydrogen content, and composites therefrom
A material with significant protection properties from galactic cosmic radiation and solar energetic particles. Hydrogen-rich benzoxazines which are particularly effective for shielding against such radiation. Benzoxazine resin meets the processing requirements for use with ultra-high molecular weight polyethylene fiber as a hydrogen-rich reinforcement: cure of the resin at 120° C. This highly reactive benzoxazine resin also exhibits low viscosity and adequate shelf life.
1. A benzoxazine resin of the chemical structure:
wherein 2≤a≤18, 0≤b≤6, and 0≤c≤6.
2. A polybenzoxazine formed by polymerization of the benzoxazine of claim 1 .
3. The polybenzoxazine according to claim 2 , formed by polymerization using a cure cycle for which a maximum temperature does not exceed about 120° C.
4. A polybenzoxazine formed by polymerization of the benzoxazine of claim 1 , wherein 6≤a≤14, 2≤b≤4, and 2≤c≤4.
5. The polybenzoxazine according to claim 4 , formed by polymerization using a cure cycle for which a maximum temperature does not exceed about 120° C.
6. The benzoxazine resin of claim 1 , wherein c is equal to b.
7. The benzoxazine resin according to claim 6 , wherein 6≤a≤18 and 1≤b≤6.
8. A polybenzoxazine formed by cure of the benzoxazine of claim 6 .
9. The polybenzoxazine according to claim 8 , formed by polymerization using a cure cycle for which a maximum temperature does not exceed about 120° C.
10. The polybenzoxazine according to claim 8 , 6≤a≤14 and 2≤b≤4.
11. The polybenzoxazine according to claim 10 , formed by polymerization using a cure cycle for which a maximum temperature does not exceed about 120° C.
12. The polybenzoxazine according to claim 8 , wherein a=12 and b=3.
13. A material, comprising:
a) 1 to 99% by weight of a polybenzoxazine formed by cure of a benzoxazine resin of the chemical structure:
wherein 2≤a≤18, 0≤b≤6, and 0≤c≤6; and
b) 99% to 1% by weight of polyethylene.
14. The material according to claim 13 , wherein the polyethylene comprises one or more of a high-density polyethylene and an ultra-high molecular weight polyethylene.
15. The material according to claim 14 , wherein 6≤a≤14, 2≤b≤4, and 2≤c≤4.
16. The material according to claim 15 , wherein a=12 and b=c=3.
17. A material, comprising:
a) 5 to 95% by volume of a polybenzoxazine formed by cure of a benzoxazine resin of the chemical structure:
wherein 6≤a≤18, 1≤b≤6, and 1≤c≤6; and
b) 95% to 5% by volume of fibrous reinforcement.
18. The material according to claim 17 , wherein the fibrous reinforcement comprises continuous fiber or woven continuous fiber.
19. The material according to claim 18 , wherein the fibrous reinforcement comprises one or more of a polyethylene fiber, carbon fiber, and boron fiber.
20. The material according to claim 17 , wherein 6≤a≤14, 2≤b≤4, and 2≤c≤4.
21. The material according to claim 20 , wherein a=12 and b=c=3.
22. The material according to claim 17 , wherein the material comprises:
a) 30% to 95% by volume of the polybenzoxazine, wherein a=12 and b=c=3, and b) 5% to 70% by volume of the fibrous reinforcement, and wherein the fibrous reinforcement is woven high density polyethylene fiber.
23. A molded object comprising the material of claim 22 .
24. A material, comprising:
a) 5 to 95% by volume of a polybenzoxazine formed by cure of a benzoxazine resin of the chemical structure:
wherein 6≤a≤18, 1≤b≤6, and 1≤c≤-6; and
b) 95% to 5% by volume of a fibrous electrical conductor.
25. The material according to claim 24 , wherein the fibrous electrical conductor comprises continuous fiber or woven continuous fiber.
26. The material of claim 25 , wherein the fibrous electrical conductor comprises copper.
27. The material according to claim 24 wherein 6≤a≤14, 2≤b≤4, and 2≤c≤4.
28. The material according to claim 27 wherein a=12 and b=c=3.