Abstract: A tire comprises a rubber composition based on at least one polymer comprising epoxide functional groups, at least one reinforcing filler and a system for crosslinking the polymer. The system for crosslinking the polymer comprises a polycarboxylic acid of general formula (I): in which A represents a covalent bond or a hydrocarbon group which comprises at least 1 carbon atom, which is optionally substituted and which is optionally interrupted by one or more heteroatoms, and an imidazole of general formula (II): in which R1 represents a hydrocarbon group or a hydrogen atom, R2 represents a hydrocarbon group, and R3 and R4 represent, independently of one another, a hydrogen atom or a hydrocarbon group, or else R3 and R4 form, together with the carbon atoms of the imidazole ring to which they are attached, a ring.

Abstract: The present invention relates to a modified polymer obtained by grafting a compound comprising at least one group Q, and at least one group A bonded together by at least, and preferably, one “spacer” group Sp in which: Q comprises an azo-carbonyl group capable of being grafted onto the polymer chain by an “ene reaction”, A comprises an associative group comprising at least one nitrogen atom, Sp is an atom or a group of atoms forming a bond between Q and A.

Abstract: The present invention relates to 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, and preferably, one “spacer” group Sp in which: Q comprises a dipole containing at least, and preferably, one nitrogen atom, capable of being grafted onto the polymer chain by [1,3]-dipolar cycloaddition, A comprises an associative group comprising at least one nitrogen atom, Sp is an atom or a group of atoms forming a bond between Q and A.

Abstract: The invention relates to a rubber composition based on at least one diene elastomer, a reinforcing filler, a chemical crosslinker and a modifier selected from compounds comprising at least one group Q, and at least one group A, which are joined to one another by at least one and preferably one spacer group Sp, wherein: Q comprises a dipole containing at least one and preferably one nitrogen atom, A comprises an associative group comprising at least one nitrogen atom, Sp is an atom or group of atoms forming a bond between Q and A. This composition has an improved balance between stiffness under moderate deformations/elongation at break and improved hysteresis properties and is therefore especially suited to the manufacture of tyres for enhancing the trade off between rolling resistance and resistance to large deformations.

Abstract: The invention relates to a tire comprising at least one rubber composition based on at least one diene elastomer, one reinforcing filler, one chemical crosslinking agent and one modifying agent, chosen from the compounds of following formula (I): where R denotes a unit comprising at least one reactive group, R1 denotes hydrogen, R2 denotes an alkylene radical comprising from 2 to 8 carbon atoms and optionally one or more heteroatoms chosen from S, N, O or Si, A denotes an oxygen or sulphur atom or an ?NH group, preferably an oxygen atom.