1,3-dipolar compound bearing an imidazole functional group
In a 1,3-dipolar compound of formula Q-A-B, Q comprises a dipole containing at least and preferably one nitrogen atom, A, which is preferably divalent, is an atom or a group of atoms connecting Q to B, and B comprises an imidazole ring. An unsaturated polymer modified by grafting the 1,3-dipolar compound is also disclosed.
1. A process for modifying, by a grafting reaction, an unsaturated polymer which exhibits at least one unsaturation, the process comprising reacting a 1,3-dipolar compound with the at least one unsaturation of the unsaturated polymer,
wherein the 1,3-dipolar compound is of formula (I):
Q-A-B (I),
wherein Q comprises a dipole containing at least one nitrogen atom,
wherein A is an atom or a group of atoms connecting Q to B, and
wherein B comprises a ring of formula (II):
wherein three of four symbols Z, Y, R, and R′ are identical or different, each representing an atom or a group of atoms, it being possible for Z and Y to form, together with carbon atoms to which they are attached, a ring, and a fourth of the four symbols Z, Y, R, and R′ denotes a direct attachment to A.
2. The process according to claim 1 , wherein R′ denotes a direct attachment to A.
3. The process according to claim 2 , wherein Z and Y are each a hydrogen atom.
4. The process according to claim 2 , wherein Z and Y form the ring together with the carbon atoms to which they are attached.
5. The process according to claim 1 , wherein R represents a hydrogen atom or a carbon-based group which can contain at least one heteroatom.
6. The process according to claim 5 , wherein R is an alkyl group containing from 1 to 12 carbon atoms.
7. The process according to claim 1 , wherein A is an aliphatic group or an aromatic group containing up to 20 carbon atoms which can contain at least one heteroatom.
8. The process according to claim 7 , wherein A is an alkylene group containing from 1 to 20 carbon atoms or an arylene group.
9. The process according to claim 1 , wherein the compound is selected from the group consisting of nitrile oxides, nitrile imines, and nitrones.
10. The process according to claim 9 , wherein Q contains a —C≡N→O unit.
11. The process according to claim 10 , wherein Q comprises a unit of formula (III):
wherein four of five symbols R 1 to R 5 are identical or different, each being an atom or a group of atoms, and a fifth of the five symbols R 1 to R 5 denotes a direct attachment to A, and
wherein neither of R 1 and R 5 is H.
12. The process according to claim 11 , wherein R 1 , R 3 , and R 5 are each an alkyl group of 1 to 6 carbon atoms.
13. The process according to claim 12 , wherein the compound is 2,4,6-trimethyl-3-((2-methyl-1H-imidazol-1-yl)methyl)benzonitrile oxide or 2,4,6-triethyl-3-((2-methyl-1H-imidazol-1-yl)methyl)benzonitrile oxide.
14. The process according to claim 9 , wherein Q contains a —C═N(→O) unit.
15. The process according to claim 14 , wherein Q comprises a unit of formula (IV) or (V):
wherein Y 1 is an aromatic group containing from 6 to 20 carbon atoms or an aliphatic group, and
wherein Y 2 , comprising a direct attachment to A, is an aliphatic group or an aromatic group comprising, on its aromatic nucleus, the direct attachment to A.
16. The process according to claim 14 , wherein the compound is of formula (IVa), (IVb), (Va), or (Vb):
17. The process according to claim 1 , wherein the 1,3-dipolar compound is reacted according to a stoichiometry of between 0 and 3 molar equivalents of imidazole ring per 100 moles of monomer units constituting the polymer.
18. The process according to claim 1 , wherein the unsaturated polymer is a diene polymer.
19. The process according to claim 18 , wherein the diene polymer is an essentially unsaturated diene elastomer selected from the group consisting of a polybutadiene, a polyisoprene, a butadiene copolymer, an isoprene copolymer, and a mixture thereof.
20. A polymer obtained by the process according to claim 1 .