Curing compositions for fluoropolymers

1. A curable composition comprising a fluoroelastomer, the fluoroelastomer comprising a nitrogen-containing cure site monomer, wherein the composition further comprises a curative selected from the group consisting of curatives of Formula I and curatives of Formula II, where Formula I is:

wherein each R1 is independently selected from H, Cl, Br, I, a C1 to C20 linear, cyclic, or branched alkyl group, a C5 to C20 aryl group, a C5 to C20 alkaryl group, a C5 to C20 aralkyl group, and NH 2;

each R2 is —OH;

each R3 is independently selected from H, Cl, Br, I, a C1 to C20 linear, cyclic, or branched alkyl group, a C5 to C20 aryl group, a C5 to C20 alkaryl group, a C5 to C20 aralkyl group, and NH 2;

each R4 is independently selected from H, Cl, Br, I, a C1 to C20 linear, cyclic, or branched alkyl group, and a C5 to C20 aryl group, a C5 to C20 alkaryl group, a C5 to C20 aralkyl group;

each R5 and R6 is independently selected from an —H, a C1 to C20 linear or branched alkyl group, a C3 to C40 alkyl group that forms a spiro group when both R5 and R6 are part of the same cyclic structure, a C5 to C40 aryl group, a C5 to C40 alkaryl group, a C5 to C40 aralkyl group that optionally forms a spiro group when both R5 and R6 are part of the same cyclic structure, an —OH, and together with one another a C═O;

provided that at least one of R1 and R3 on each ring is an —NH 2 ; and

Formula II is:

wherein each R1 is independently selected from H, Cl, Br, I, a C1 to C20 linear, cyclic, or branched alkyl group, a C5 to C20 aryl group, a C5 to C20 alkaryl group, a C5 to C20 aralkyl group, and NH 2 ;

each R2 is —OH;

each R3 is independently selected from H, Cl, Br, I, a C1 to C20 linear, cyclic or branched alkyl group, a C5 to C20 aryl group, a C5 to C20 alkaryl group, a C5 to C20 aralkyl group, and NH 2 ;

each R4 is independently selected from H, Cl, Br, I, a C1 to C20 linear, cyclic or branched alkyl group, a C5 to C20 aryl group, a C5 to C20 alkaryl group, and a C5 to C20 aralkyl group;

each R5 is independently selected from an —H, a C1 to C20 linear, cyclic, or branched alkyl group, a C5 to C40 aryl group, a C5 to C40 alkaryl group, and a C5 to C40 aralkyl group;

provided that at least one of R1 and R3 on each ring is an —NH 2 .

2. A curable composition according to claim 1 wherein each R1 and R4 is hydrogen.

3. A curable composition according to claim 1 , wherein each R5 and R6 of formula I is selected from a —H and a —CH 3 .

4. A curable composition according to claim 1 , wherein each R5 and R6 of formula I is —CH 3 .

5. A curable composition according to claim 1 , wherein R5 of formula II is a phenyl group.

6. A curable composition according to claim 1 , wherein the fluoroelastomer is perfluorinated.

7. A curable composition according to claim 1 , wherein the fluoroelastomer is a copolymer comprising tetrafluoroethylene, perfluoromethylvinylether, and a cyano-containing cure site monomer.

8. A curable composition according to claim 7 wherein the cyano-containing cure site monomer is 8-cyano-2-oxaperfluoro-1-oxtene.

9. A curable composition according to claim 1 , wherein the fluoroelastomer comprises interpolymerized units of from 50 to 75 mole percent of tetrafluoroethylene; from 25 to 45 mole percent of perfluoromethylvinylether; and from 0.5 to 5 mole percent of a cure site monomer.

10. A curable composition according to claim 1 , wherein the fluoroelastomer is partially fluorinated.

11. A curable composition according to claim 10 , wherein the fluoroelastomer comprises interpolymerized units of from 20 to 80 mole percent vinylidene fluoride.

12. A curable composition according to claim 1 , further comprising carbon black.

13. A method comprising curing a curable composition according to claim 1 .

14. A cured article prepared by the method of claim 13 .