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 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 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: Triblock polymers of formula A-B-C, in which the symbol A represents a polystyrene block, and the symbol B represents a statistical copolymer block with a glass transition temperature of less than-10° C., are provided. The statistical copolymer comprises units of a 1,3-diene and more than 50 mol % of ethylene units. The symbol C represents a polyethylene block with a melting temperature of greater than 90° C. The triblock polymers exhibit good elastic recovery.

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: A diorganomagnesium compound of formula RB—Mg—RA is provided. RB is different from RA, RB comprises a benzene nucleus substituted with a magnesium atom, one of the carbon atoms of the benzene nucleus ortho to the magnesium is 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 is substituted with a methyl, an ethyl or an isopropyl. RA is 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: The invention relates to an organomagnesium compound of formula RB—(Mg—RA)m—Mg—RB, RB comprising a benzene nucleus substituted with the magnesium atom, one of the carbon atoms of the benzene nucleus ortho to the magnesium being substituted with a methyl, an ethyl or 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 a divalent aliphatic hydrocarbon-based chain, optionally interrupted with one or more oxygen or sulfur atoms or with one or more arylene groups, m being a number greater than or equal to 1, preferably 1. When used as co-catalyst of a rare-earth metallocene, it allows the synthesis of telechelic polymers.

Abstract: A process for preparing a polyethylene bearing a terminal ketone function or a copolymer of ethylene and a 1,3-diene and optionally a vinylaromatic compound which contains more than 50 mol % of ethylene and bears a terminal ketone function is provided. The process comprises a polymerization reaction of the monomers in the presence of a borohydrido-neodymocene complex and an organomagnesium reagent, followed by a coupling reaction with a compound containing a nitrile function, and then a hydrolysis reaction.

Abstract: A process for synthesizing 5-((2-methyl-1H-imidazol-1-yl)methyl)furan-2-carbaldehyde from a mixture comprising a carbohydrate, an alkali or alkaline-earth metal chloride, hydrochloric acid, water, an organic solvent, namely a water-insoluble polar aprotic solvent, and optionally a phase-transfer agent, proceeds via the formation of 5-(chloromethyl)furan-2-carbaldehyde, without isolating this synthesis intermediate. A process also synthesizes a compound of formula (III) below: from 5-((2-methyl-1H-imidazol-1-yl)methyl)furan-2-carbaldehyde.

Abstract: A copolymer of a 1,3-diene and of an olefin is provided. The copolymer bears, at one of its chain ends, a functional group of formula —CH2—CH(CH3)—COOZ, Z being a hydrogen atom or a carbon-comprising group. A process of preparation of the copolymer is also provided. The olefin is ethylene or a mixture of ethylene and of an ?-monoolefin.

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 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: 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 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 preparing a random copolymer based on at least one acyclic diene monomers and on at least one cyclic diene monomer is provided. The process comprises a step of copolymerization, in the presence of a polar agent and an anionic initiator in a polymerization solvent, of at least one acyclic diene monomer and of at least one cyclic diene monomer of which one C?C double bond is endocyclic and conjugated to an exocyclic C?C double bond, at a polymerization temperature below 80° C. A molar ratio of the polar agent/function(s) of the anionic initiator capable of initiating anionic polymerization being greater than 0.1. Copolymers based on at least one acyclic diene monomer and on at least one cyclic diene monomer and the compositions containing them are also provided.

Abstract: A method for synthesizing a thermoplastic elastomer comprising at least one polydiene block and at least one other poly(?-methylstyrene) block comprises: polymerizing at least one diene monomer in a starting reaction medium comprising an anionic polymerization initiator and an aprotic non-polar solvent; polymerizing ?-methylstyrene to the living polydiene chain obtained in the preceding step comprising: maintaining the reaction medium containing the living diene elastomer obtained previously and ?-methylstyrene at a positive temperature, below the ceiling temperature for the polymerization of ?-methylstyrene; cooling the reaction medium obtained at the end of step a., to a temperature below 0° C.; simultaneously, successively or prior to the cooling step, adding a purified aprotic polar solvent to the reaction medium with a volume ratio of the polar solvent to the non-polar solvent of less than 1; and propagating the polymerization of ?-methylstyrene to the living polydiene chain.