Graft polymer to which combined nitrogen molecules are grafted

1. A modified polymer obtained by grafting of a compound comprising at least one group Q and at least one group A, bonded together by at least, one “spacer” group Sp in which:

Q comprises a comprises a nitrile oxide, nitrone or nitrile imine functional group,

A comprises an associative group comprising at least one nitrogen atom, and corresponds to one of the following formulae (II), (III), (IV), (V), or (VI):

where:

R denotes a hydrocarbon group which may optionally contain heteroatoms,

X denotes an oxygen or sulphur atom or a group —NH

Sp is an atom or a group of atoms forming a bond between Q and A.

2. The modified polymer according to claim 1 , wherein the polymer is a diene elastomer.

3. The modified polymer according to claim 2 , wherein the diene elastomer is essentially saturated.

4. The modified polymer according to claim 2 , wherein the diene elastomer is essentially unsaturated.

5. The modified polymer according to claim 1 , wherein the group Q is a group of the following formula (VII), (VIII) or (IX)

R 4 —C≡N→O  (VIII)

R 5 —C≡N→N—R 6   (IX)

in which R1 to R6 are independently selected from the group consisting of a spacer group Sp, a hydrogen atom, a linear or branched C1-C20 alkyl group, a linear or branched C3-C20 cycloalkyl group, a linear or branched C6-C20 aryl group and a group of formula (X)

in which n represents 1, 2, 3, 4 or 5 and each Y independently represents a spacer group Sp, an alkyl group or a halide.

6. The modified polymer according to claim 1 , wherein the “spacer” group is a linear or branched C1-C24 alkyl chain comprising one or more heteroatoms selected from nitrogen, sulphur, silicon or oxygen atoms.

7. The modified polymer according to claim 1 , wherein the group Q is a group of formula (XIa) or (XIb):

in which R7 and R8 independently represent a C1-C5 alkyl group or a halide and R3 is selected from the group consisting of a spacer group Sp, a hydrogen atom, a linear or branched C1-C20 alkyl group, a linear or branched C3-C20 cycloalkyl group, a linear or branched C6-C20 aryl group and a group of formula (X)

in which n represents 1, 2, 3, 4 or 5 and each Y independently represents a spacer group Sp, an alkyl group or a halide and the group A is a group of formula (XII)

8. The modified polymer according to claim 1 , wherein the compound is selected from the group consisting of compounds of the following formulae (XIII), (XIV), (XV), (XVI), (XVII), (XVIII), (XIX), (XX) and (XXI):

wherein R3 is selected from the group consisting of a spacer group Sp, a hydrogen atom, a linear or branched C1-C20 alkyl group, a linear or branched C3-C20 cycloalkyl group, a linear or branched C6-C20 aryl group and a group of formula (X)

in which n represents 1, 2, 3, 4 or 5 and each Y independently represents a spacer group Sp, an alkyl group or a halide.

9. The modified polymer according to claim 1 , wherein the compound is selected from the group consisting of compounds of the following formulae (XXII) and (XXIII)

in which R is independently selected from the group consisting of a spacer group Sp, a hydrogen atom, a linear or branched C1-C20 alkyl group, a linear or branched C3-C20 cycloalkyl group, a linear or branched C6-C20 aryl group, and a group of formula (X)

in which n represents 1, 2, 3, 4 or 5 and each Y independently represents a spacer group Sp, an alkyl group or a halide.

10. A process for the preparation of a modified polymer according to claim 1 , comprising:

grafting onto a polymer comprising at least one unsaturation a compound comprising at least one group Q, and at least one group A bonded to each other by at least one “spacer” group Sp, wherein Q, A, and Sp are as defined in claim 1 , by [3+2] cycloaddition of the group Q onto the unsaturation of the polymer.

11. The process for the preparation of a modified polymer according to claim 10 , wherein the polymer is a diene elastomer.

12. The modified polymer according to claim 1 , wherein there is one “spacer” group Sp.

13. The modified polymer according to claim 1 , wherein X denotes an oxygen atom.

14. The modified polymer according to claim 3 , wherein the diene elastomer is selected from the group consisting of ethylene-propylene-diene monomer (EPDM) copolymers and butyl rubbers.

15. The modified polymer according to claim 4 , wherein the diene elastomer is selected from the group consisting of natural rubber, synthetic polyisoprenes, polybutadienes, butadiene copolymers, isoprene copolymers and mixtures of these elastomers.

16. The modified polymer according to claim 6 , wherein the “spacer” group is a linear or branched C1-C10 alkyl chain comprising one or more heteroatoms selected from nitrogen, sulphur, silicon or oxygen atoms.

17. The modified polymer according to claim 7 , wherein R7 and R8 each independently represent a methyl group or a chlorine atom.