Abstract: A catalytic system based on at least one rare-earth metallocene and an organomagnesium reagent as co-catalyst of formula RB—(Mg—RA)m—Mg—RB is provided. According to the formula, RB comprises a benzene nucleus substituted with the magnesium atom. One of the carbon atoms of the benzene nucleus ortho to the magnesium is substituted with a methyl, an ethyl or an isopropyl or forms a ring with the carbon atom which is its closest neighbour and which is meta to the magnesium. The other carbon atom of the benzene nucleus ortho to the magnesium is substituted with a methyl, an ethyl or an isopropyl. RA is a divalent aliphatic hydrocarbon-based chain, optionally interrupted with one or more oxygen or sulfur atoms or with one or more arylene groups. The m is a number greater than or equal to 1, preferably 1. The catalytic system allows the synthesis of dienic and/or ethylenic telechelic polymers.

Abstract: A rubber composition contains: an elastomer matrix comprising at least one diene elastomer comprising epoxide functions, at least one reinforcing filler, and a system for crosslinking said polymer, comprising at least one organopolyphosphorus compound of general formula (I) in which A represents a covalent bond or a hydrocarbon group comprising at least 1 carbon atom, which is optionally substituted and which optionally comprises one or more heteroatoms, and the Rs represent, independently of one another, a hydrocarbon group comprising at least 1 carbon atom or a hydrogen atom.

Abstract: A triblock polymer of formula B-A-B is provided. According to the formula, the symbol A represents a “central” block which is a statistical copolymer comprising units of a 1,3-diene and more than 50 mol % of ethylene units. The symbols B each represent an “end” block which is a polyethylene with a melting point of greater than 90° C. and a number-average molar mass of greater than or equal to 2000 g/mol and less than or equal to 10 000 g/mol. The polymer has improved rheological properties relative to a statistical copolymer based on ethylene and 1,3-diene of the same microstructure without changing its mechanical and dynamic or thermal properties.

Abstract: A process for preparing a multiblock polymer by statistical copolymerization of a mixture containing ethylene and a 1,3-diene and subsequent polymerization of ethylene in the presence of a rare-earth metallocene and an organomagnesium reagent RB—(Mg—RA)m—Mg—RB or X—Mg—RA—Mg—X is provided. According to the formula, RA is a divalent aliphatic hydrocarbon-based chain optionally interrupted with one or more oxygen or sulfur atoms or arylene groups, RB comprises a benzene nucleus substituted with the Mg atom, one of the carbon atoms of the benzene nucleus ortho to the Mg is substituted with a methyl, an ethyl or an isopropyl or forms a ring with the carbon atom which is its closest neighbour and which is meta to the Mg. The other carbon atom of the benzene nucleus ortho to the Mg is substituted with a methyl, ethyl or isopropyl, X being a halogen atom, m being greater than or equal to 1.

Abstract: A telechelic polymer of formula Z1-POLY-Z2 is provided. The term “POLY” denotes a polymer chain comprising units of a 1,3-diene, ethylene units and cyclic units, 1,2-cyclohexane units, Z1 and Z2 denoting a group containing a function, Z1 and Z2 being identical. The polymer has a macrostructure defined by a dispersity of less than 1.5 or by a number-average molar mass of greater than 10 000 g/mol.

Abstract: A catalytic system based on at least one rare-earth metallocene and as co-catalyst an organomagnesium reagent of formula X—Mg—RA—Mg—X is provided. In the formula, RA is a divalent aliphatic hydrocarbon-based chain, optionally interrupted with an oxygen atom, a sulfur atom or with an arylene group, and X is a halogen atom. The catalytic system allows the synthesis of dienic and/or ethylenic telechelic polymers.

Abstract: A catalytic system based on at least one metallocene and on a diorganomagnesium compound of formula RB—Mg—RA is provided, RB being different from RA and comprising a benzene nucleus substituted with a magnesium atom, one of the carbon atoms of the benzene nucleus ortho to the magnesium being substituted with a methyl, an ethyl, an isopropyl or forming a ring with the carbon atom which is its closest neighbour and which is meta to the magnesium, the other carbon atom of the benzene nucleus ortho to the magnesium being substituted with a methyl, an ethyl or an isopropyl, RA being an alkyl, a cycloalkyl or a benzyl, which may be substituted or unsubstituted. The catalytic system makes it possible to increase the functional group content in the synthesis of a functional polymer.

Abstract: Disclosed is a compound of formula (I) below: in which: T is chosen from the group consisting of CN+—O?, CH?NOH and CHO; A represents a C6-C14 arenediyl ring optionally substituted with one or more identical or different, preferably saturated, linear or branched aliphatic hydrocarbon chains; represents a divalent C5-C12 hydrocarbon group optionally comprising one or more heteroatoms; and X1, X2 and X3, which may be identical or different, represent a hydrogen atom, a C1-C6 alkyl or a C6-C14 aryl. Also disclosed is a process for synthesizing compounds of formula (I), a modified polymer obtained by grafting the compound of formula (I) with T=CN+—O?, a composition based on the modified polymer and an additive, and to a composition based on at least one additive and at least one compound of formula (I) with T=CN+—O?.

Abstract: The invention relates to a diorganomagnesium compound of formula RB—Mg—RA, RA being different from R8, RA being a polymer chain containing units of a monomer chosen from the group of monomers consisting of 1,3-dienes, aromatic ?-monoolefins and mixtures thereof, RB comprising a benzene nucleus substituted with a magnesium atom, one of the carbon atoms of the benzene nucleus ortho to the magnesium being substituted with a methyl, an ethyl, an isopropyl or forming a ring with the carbon atom which is its closest neighbour and which is meta to the magnesium, the other carbon atom of the benzene nucleus ortho to the magnesium being substituted with a methyl, an ethyl or an isopropyl, on condition that if one of the two ortho carbon atoms is substituted with an isopropyl, the second ortho carbon atom is not substituted with an isopropyl.

Abstract: The invention relates to a composite based on at least one, preferably metallic, reinforcing element and on a rubber composition based on at least a. an epoxidized diene elastomer, b. a reinforcing filler, and c.

Abstract: The invention relates to a diorganomagnesium compound of formula RB—Mg—RA, RB being different from RA, RB comprising a benzene nucleus substituted with a magnesium atom, one of the carbon atoms of the benzene nucleus ortho to the magnesium being substituted with a methyl, an ethyl, an isopropyl or forming a ring with the carbon atom which is its closest neighbour and which is meta to the magnesium, the other carbon atom of the benzene nucleus ortho to the magnesium being substituted with a methyl, an ethyl or an isopropyl, RA being an alkyl, a cycloalkyl or a benzyl, which may be substituted or unsubstituted, which diorganomagnesium compound is other than n-butylmesitylmagnesium. When used as co-catalyst of a metallocene, it makes it possible to increase the functional group content in the synthesis of a functional polymer.

Abstract: A process for manufacturing a masterbatch comprises the following steps: (a) bringing at least one initial polymer comprising at least one carbon-carbon unsaturation into contact with at least one 1,3-dipolar grafting agent bearing at least one nitrile oxide dipole in the presence of at least one organophosphorus additive selected from the group consisting of phosphoric acid triesters, phosphonates, phosphinates, phosphine oxides and the mixtures of these compounds, and (b) recovering the masterbatch obtained in the preceding step. The masterbatch and compositions containing it and also tires comprising such compositions are also disclosed.

Abstract: A diblock polymer composed of a first block and a second block is provided. The first block is a statistical copolymer comprising units of a 1,3-diene and more than 50 mol % of ethylene units. The second block is a polyethylene with a melting point above 90° C. and a number-average molar mass greater than or equal to 2000 g/mol and less than or equal to 10 000 g/mol. Such a diblock polymer has improved rheology compared to a statistical copolymer of the same microstructure and of the same macrostructure as the first block of the diblock polymer.

Abstract: A modified polymer is obtained by grafting of at least one compound of formula (I) onto at least one unsaturation of the initial polymer chain in which Q represents a dipole comprising at least one nitrogen atom; A represents a divalent heteroaromatic ring optionally substituted with one or more identical or different linear or branched aliphatic hydrocarbon-based chains, optionally substituted or interrupted with one or more heteroatoms; E represents a divalent hydrocarbon-based group which may optionally contain one or more heteroatoms; R1 represents a hydrogen atom or a C1-C20 alkyl group; and Y and Z, which may be identical or different, each represent a hydrogen atom or a hydrocarbon-based chain, Y and Z together also possibly forming a ring, notably an aromatic ring, with the carbon atoms of the imidazole ring to which they are attached.

Abstract: A modified polymer is obtained by grafting at least one compound of formula (I) to at least one unsaturation of the chain of an initial polymer in which Q represents a dipole comprising at least one nitrogen atom; A represents an arenediyl ring, optionally substituted by one or more hydrocarbon-based chains, which are identical or different, independent of one another, and are optionally substituted or interrupted by one or more heteroatoms; E represents a divalent hydrocarbon-based bonding group which may optionally contain one or more heteroatoms; R1, R2 and R3 represent, independently of one another, a hydrogen atom or a hydrocarbon-based chain which is optionally substituted or interrupted by one or more heteroatoms; and n is an integer having a value greater than or equal to 1.

Abstract: A block polymer comprising a first block and a second block is provided. The first block contains aromatic ?-mono-olefin units, and the second block contains both 1,3-diene units and mono-olefin units.

Abstract: A rubber composition based on a reinforcing filler and on an elastomer comprising units of a 1,3-diene monomer and bearing carbonate functions, each present in a 1,3-dioxolan-2-one ring is provided. The composition has improved reinforcement.

Abstract: A block polymer comprising a first block and a second block is provided. The first block contains aromatic ?-mono-olefin units, and the second block contains both 1,3-diene units and mono-olefin units.

Abstract: A process for modifying a natural rubber is provided. The process comprises at least the following steps: i. providing at least one natural rubber and epoxidizing the natural rubber to obtain an epoxidized natural rubber, or providing a pre-epoxidized natural rubber, ii. grafting, to the epoxidized natural rubber or to the pre-epoxidized natural rubber, at least one 1,3-dipolar compound having at least one nitrogen atom. A modified natural rubber capable of being obtained by the process and also rubber compositions based on the modified natural rubber is also provided.

Abstract: A rubber composition based on a reinforcing filler and on an elastomer comprising units of a 1,3-diene monomer and bearing carbonate functions, each present in a 1,3-dioxolan-2-one ring is provided. The composition has improved reinforcement.