Polymerizable ionic liquid comprising aromatic carboxylate anion

1. A polymerizable ionic liquid comprising a cation and an aromatic carboxylate anion; wherein the cation, anion, or both comprise a free-radically polymerizable group and at least one free-radically polymerizable group is selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether.

2. The polymerizable ionic liquid of claim 1 wherein the cation comprises a free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether and the anion lacks a free-radically polymerizable group.

3. The polymerizable ionic liquid of claim 1 wherein the anion comprises a free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether and the cation lacks a free-radically polymerizable group.

4. The polymerizable ionic liquid of claim 1 wherein the anion and cation each comprise at least one free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether.

5. The polymerizable ionic liquid of claim 2 wherein the free-radically polymerizable group is a (meth)acrylate group.

6. The polymerizable ionic liquid of claim 1 wherein the cation is a substituted ammonium or phosphonium cation.

7. The polymerizable ionic liquid of claim 6 wherein the ionic liquid has the general formula:

wherein

X is nitrogen or phosphorus;

R3 and R4 are independently alkyl or heteroalkyl, and at least one R3 or R4 comprises a free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether;

D comprises an aromatic moiety and optionally comprises a linking group between the carboxylate end group and aromatic moiety and/or optionally comprises a linking group between the aromatic moiety and R4; and

b is 0-2.

8. The polymerizable ionic liquid of claim 7 wherein the free-radically polymerizable groups are (meth)acrylate groups.

9. The polymerizable ionic liquid of claim 7 wherein R3 are alkyl or heteroalkyl groups and R4 comprises the free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether.

10. The polymerizable ionic liquid of claim 7 wherein R4 are alkyl or heteroalkyl groups and at least one R3 comprises a free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether.

11. The polymerizable ionic liquid of claim 7 wherein R3 and R4 both comprise at least one free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether.

12. The polymerizable ionic liquid claim 10 wherein R3 comprises at least two polymerizable groups selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether.

13. The ionic liquid of claim 1 wherein the cation is a substituted imidazolium cation.

14. The ionic liquid of claim 13 wherein the ionic liquid has the general formula:

wherein

R3 and R4 are independently alkyl or heteroalkyl, and at least one R3 or R4 comprises a free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether;

D comprises an aromatic moiety and optionally comprises a linking group between the carboxylate end group and aromatic moiety and/or optionally comprises a linking group between the aromatic moiety and R4;

c is 0 to 3; and

b is 0-2.

15. The polymerizable ionic liquid of claim 14 wherein the free-radically polymerizable groups are (meth)acrylate groups.

16. The polymerizable ionic liquid of claim 14 wherein R3 are alkyl or heteroalkyl groups and R4 comprises a free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether.

17. The polymerizable ionic liquid of claim 14 wherein R4 are alkyl or heteroalkyl groups and R3 comprises a free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether.

18. The polymerizable ionic liquid of claim 14 wherein R3 and R4 both comprise a free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether.

19. The polymerizable ionic liquid of claim 7 wherein D comprises one, two, or three aromatic rings that are optionally fused.

20. The ionic liquid of claim 1 wherein the ionic liquid has an air to nitrogen curing exotherm of at least 0.90.

21. The ionic liquid of claim 1 wherein the polymerizable ionic liquid has a melting point below 25° C.

22. A curable composition wherein the composition comprises at least one polymerizable ionic liquid according to claim 1 and at least one other free-radically polymerizable monomer, oligomer, or polymer.

23. The polymerizable ionic liquid of claim 7 wherein two R3 groups are alkyl, one R3 comprises a free-radically polymerizable group, and R4 comprises a free-radically polymerizable group selected from the group consisting of (meth)acrylamide, (meth)acrylate, and vinyl ether.

24. The polymerizable ionic liquid of claim 23 wherein the R3 comprising the free-radically polymerizable group further comprises an aromatic linking group.