US3905941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyquinoxalines and method of preparation
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1973-10-31
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Granted: 1975-09-16
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Expires: 1993-10-31
Abstract
Abstract Linear polyquinoxalines are produced by the reaction of an aromatic quinoxaline having two furan endcaps or substituents with an aromatic olefinic end-capped monomer. These linear polymers have an alicyclic endooxy linkage repeated throughout the polymer backbone chain where the furan end-cap combines with the olefin end-cap by Diels-Alder reaction. The linear polymer is converted to a higher performance polymer by heating in a range of 200* to 400*C whereupon the endooxy linkage is aromatized in situ. The polyquinoxalines so prepared are suitable for use in severe environments at temperatures up to 350*C.
Inventors
- 👤 Robert J Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:40
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/12; C08G73/126; C08G73/0683; C08G73/0694
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
27 words
A METHOD FOR MAKING POLYQUINOXALINE POLYMERS COMPRISING: A. REACTING AT TEMPERATURES RANGING FROM 25* TO 300*C, EQUIMOLAR AMOUNT OF (I) A DIFURAN END-CAPPED MONOMER HAVING THE FORMULA
Claim 2
Independent Claim
27 words
A METHOD FOR MAKING POLYQUINOXALINE POLYMERS COMPRISING: A. REACTING AT TEMPERATURES RANGING FROM 25* TO 300*C, EQUIMOLAR AMOUNT OF (I) A DIFURAN END-CAPPED MONOMER HAVING THE FORMULA
Claim 3
Dependent Claim
22 words
A POLYQUINOXALINE CONSISTING ESSENTIALLY OF THE STRUCTURE: -(E)-(R)-(E)-(R''))N WHERE R IS A DIFUNCTIONAL AROMATIC QUINOXALINE RADICAL SELECTED FROM THE GROUP CONSISTING OF
Claim 4
Dependent Claim
22 words
A POLYQUINOXALINE CONSISTING ESSENTIALLY OF THE STRUCTURE: -(E)-(R)-(E)-(R''))N WHERE R IS A DIFUNCTIONAL AROMATIC QUINOXALINE RADICAL SELECTED FROM THE GROUP CONSISTING OF
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |