Claims
- 1. Polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of at least one polyamine, at lease one tetracarboxylic dianhydride and a dicarboxylic endcap having a formula selected from the group consisting of: whereinR1 is selected from the group consisting of where R is either hydrogen or an alkyl radical of 1 to 4 carbons,R2 is selected from the group consisting of —OH, NH2, F and Cl radicals, and R3 is selected from the group consisting of H, OH, NH2, F, Cl and lower alkylene radicals.
- 2. A process of preparing polyimides having improved oxidative-stability which comprises polymerizing effective amounts of at least one polyamine with at least one tetracarboxylic dianhydride and a dicarboxylic endcap having a formula selected from the group consisting of: whereinR1 is selected from the group consisting of where R is either hydrogen or an alkyl radical of 1 to 4 carbons,R2 is selected from the group consisting of —OH, NH2, F and Cl radicals, and R3 is selected from the group consisting of H, OH, NH2, F, Cl and lower alkylene radicals.
- 3. Polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of at least one polyamine, at lease one tetracarboxylic dianhydride and 7-hydroxy-5-norbornene-2,3-dicarboxylic anhydride.
- 4. Polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of at least one polyamine, at lease one tetracarboxylic dianhydride and 7-hydroxy-5-norbornene-2,3-dicarboxylic monomethyl ester-acid.
- 5. Polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of at least one polyamine, at lease one tetracarboxylic dianhydride and 7,7-diflouro-5-norbornene-2,3-dicarboxylic monomethyl ester-acid.
- 6. Polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of at least one polyamine, at lease one tetracarboxylic dianhydride and 7,7-dihydroxy-5-norbornene-2,3-dicarboxylic anhydride.
- 7. Polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of at least one polyamine, at lease one tetracarboxylic dianhydride and 7,7-diamine-5-norbornene-2,3-dicarboxylic monomethyl ester-acid.
- 8. Polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of at least one polyamine, at least one tetracarboxylic dianhydride and a dicarboxylic endcap having a formula selected from the group consisting of: whereinR1 is selected from the group consisting of where R is either hydrogen or an alkyl radical of 1 to 4 carbons,R2 is selected from the group consisting of —OH, NH2, F and Cl radicals, R3 is selected from the group consisting of H, OH, NH2, F, Cl, and lower alkylene radicals and either R2 or R3 is a NH2 radical.
- 9. Polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of at least one polyamine, at least one tetracarboxylic dianhydride and a dicarboxylic endcap having a formula selected from the group consisting of: whereinR1 is selected from the group consisting of where R is either hydrogen or an alkyl radical of 1 to 4 carbons,R2 is selected from the group consisting of —OH, NH2, F and Cl radicals, R3 is selected from the group consisting of H, OH, NH2, F, Cl, and lower alkylene radicals and either R2 or R3 is a lower alkylene radical.
- 10. Polyimides having improved thermal-oxidative stability derives from the polymerization of effective amounts of at least one polyamine, at least one tetracarboxylic dianhydride and a dicarboxylic endcap having a formula selected from the group consisting of: whereinR1 is where R is an alkyl radical of 1 to 4 carbons,R2 is selected from the group consisting of —OH, NH2, F and Cl radicals, and R3 is selected from the group consisting of H, OH, NH2, F, Cl and lower alkylene radicals.
- 11. Polyimides having improved thermal-oxidative stability derives from the polyamerization of effective amounts of at least one polyamine, at least one tetracarboxylic dianhydride and a dicarboxylic endcap having a formula selected from the group consisting of: whereinR1 is where R is methyl,R2 is selected from the group consisting of —OH, NH2, F and Cl radicals, and R3 is selected from the group consisting of H, OH, NH2, F, Cl and lower alkylene radicals.
- 12. Polyimides having improved thermal-oxidative stability derives from the polymerization of effective amounts of at least one polyamine, at least one tetracarboxylic dianhydride and a dicarboxylic endcap having a formula selected from the group consisting of: whereinR1 is R2 is selected from the group consisting of —OH, NH2, F and Cl radicals, and R3 is selected from the group consisting of H, OH, NH2, F, Cl and lower alkylene radicals.
- 13. Polyimides having improved thermal-oxidative stability derives from the polymerization of effective amounts of at least one polyamine, at least one tetracarboxylic dianhydride and a dicarboxylic endcap having a formula selected from the group consisting of: whereinR1 is where R is H,R2 is selected from the group consisting of —OH, NH2, F and Cl radicals, and R3 is selected from the group consisting of H, OH, NH2, F, Cl and lower alkylene radicals.
- 14. Polyimides having improved thermal-oxidative stability derives from the polymerization of effective amounts of at least one polyamine, at least one tetracarboxylic dianhydride and a dicarboxylic endcap having a formula selected from the group consisting of: whereinR1 is where R is an alkyl radical of 1 to 4 carbons,R2 is selected from the group consisting of —OH, NH2, F and Cl radicals, and R3 is selected from the group consisting of H, OH, NH2, F, Cl and lower alkylene radicals and where R2 and R3 are the same radicals.
- 15. The polyimides of claim 14 wherein R2 and R3 are different radicals.
- 16. The polyamides of claim 10 wherein R2 is NH2 and R3 is OH.
- 17. The polyimides of claim 10 wherein R2 and R3 are Cl radicals.
- 18. A process of preparing polyimides having improved oxidative-stability which comprises polymerizing effective amounts of at least one polyamine with at least one tetracarboxylic dianhydride and a dicarboxylic endcap having a formula selected from the group consisting of: whereinR1 is selected from the group consisting of —N—N(CH3)2 and where R is either hydrogen or an alkyl radical of 1 to 4 carbons,R2 is selected from the group consisting of —OH, NH2, F and Cl radicals, R3 is selected from the group consisting of H, OH, NH2, F, Cl and lower alkylene radicals, wherein N moles of the tetracarboxylic dianhydride, N+1 moles of the diamine and 2.0 moles of the dicarboxylic endcap are polymerized with the value of N ranging from 2 to 30.
- 19. The process of claim 18 where R2 and R3 are different radicals.
- 20. The process of claim 18 wherein R2 and R3 are the same radicals.
- 21. The process of claim 18 wherein the polyamine is a mixture of more than one aromatic diamine.
- 22. The process of claim 18 wherein the polyimides are derived from at least two aromatic polyamines and at least two tetracarboxylic dianhydrides.
ORIGIN OF INVENTION
The invention described herein was made by an employee of the United States Government and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or therefor.
US Referenced Citations (14)