Abstract: Borohydride metallocene complex of lanthanide, preparation process, catalytic system incorporating it, copolymerization of olefins employing catalytic system and ethylene/butadiene copolymer, the butadiene units comprise 1,2-cyclohexane or 1,2- and 1,4-cyclohexane links. The complex corresponds to of formulae A and/or B: where, in A two ligands Cp1 and Cp2, each of a fluorenyl group, are connected to the lanthanide Ln, where, in B, a ligand molecule, composed of two fluorenyl groups Cp1 and Cp2 are connected via bridge P of formula MR1R2, is an element from group IVa, R1 and R2, which are identical or different, represent an alkyl group comprising from 1 to 20 carbon atoms, connected to lanthanide Ln, L is alkali metal, N is molecule of a complexing solvent, x is integral or non-integral number ?0 and p is integer ?1.

Abstract: Borohydride metallocene complex of lanthanide, preparation process, catalytic system incorporating borohydride metallocene complex, process for copolymerization of olefins employing catalytic system. The complex corresponds to one or other of formulae A and B: where, in A, two ligands Cp1, Cp2, each composed of a cyclopentadienyl group, are connected to the lanthanide Ln, such as Nd, and where, in B, a ligand molecule, composed of two cyclopentadienyl groups Cp1, Cp2 connected to one another via a bridge P of formula MR1R2, M is an element from group IVa, and R1 and R2, which are identical or different, represent an alkyl group comprising from 1 to 20 carbon atoms, is connected to the lanthanide Ln, L is alkali metal, N is molecule of a complexing solvent, x is integral or non-integral number?0, p is integer?than 1 and y is integer?0.

Abstract: Elastomer composition comprising at least, as predominant elastomer, a thermoplastic SIBS elastomer comprising a “polyisobutylene” block and, at least one of the ends of the “polyisobutylene” block, a thermoplastic block of specific structure having a Tg greater than or equal to 100° C. The elastomer composition according to the invention may be used as an elastomer layer impermeable to the inflation gases in an inflatable object. This inflatable object is, in particular, an inner tube or a pneumatic tyre for a motor vehicle.

Abstract: The present invention relates to a novel organometallic compound based on a divalent metal belonging to the 2nd column of the Periodic Table that can be used as an alkylating agent in a catalytic system based on a rare-earth metal. This novel compound corresponds to the formula: in which, M is a metal belonging to the 2nd column of the Periodic Table, chosen from Be, Mg, Sr, Ba, and Ra; R1, R2, R3 and R4 are hydrogen atoms or alkyl or aryl substituents, optionally bonded together to form at least one ring or at least one aromatic ring; R and R? denote alkyl or aryl substituents; L is a Lewis base; x is an integer from 0 to 4; m is an integer greater than or equal to 0; and n is an integer greater than or equal to 1.

Abstract: The invention relates to a process for preparing a rare-earth organophosphate in the form of a fluid or not very viscous solution that can be used as is for the preparation of a “preformed” catalyst system intended, in particular, for the cis-1,4 stereospecific polymerization of conjugated dienes.

Abstract: La present invention relates to a multi-component catalytic system that can be used for the cis-1,4 stereospecific polymerization of conjugated dienes. The system is based on: (i) a rare-earth complex of Formula (II) Ln(A)3(B)n, Ln being a rare-earth metal, A a ligand, B a Lewis base or a solvent molecule and n a number from 0 to 3; (ii) an alkylating agent; (iii) a compound based on an aromatic ring and having at least two heteroatoms chosen from the elements O, N, S, P, and corresponding to the Formula (III): in which the R groups each denote hydrogen, an alkyl radical optionally comprising one or more heteroatoms (N, O, P, S, Si) or one or more halogen atoms, a halogen atom, a group based on one or more heteroatoms (N, O, P, S, Si); x and y are integers from 0 to 6; D is a group having a chemical function, one of the atoms of which has a non-bonding pair; L being an atom from column 1 of the Periodic Table.

Abstract: A borohydride metallocene complex of a lanthanide, its process of preparation, a catalytic system incorporating it, a process for the copolymerization of olefins employing this catalytic system and an ethylene/butadiene copolymer obtained by this process, the butadiene units of which comprise 1,2-cyclohexane or 1,2- and 1,4-cyclohexane links.

Abstract: A borohydride metallocene complex of a lanthanide, its process of preparation, a catalytic system incorporating a borohydride metallocene complex and a process for the copolymerization of olefins employing this catalytic system.

Abstract: Inflatable article equipped with an elastomer layer impermeable to inflation gases, said elastomer layer comprising at least, as the predominant elastomer, a thermoplastic SIBS elastomer comprising a polyisobutylene block comprising an amount of units derived from one or more conjugated dienes ranging from 0.5% to 6% by weight relative to the weight of the polyisobutylene block, and, at least one of the ends of the polyisobutylene block, a stirenic block representing at most 16% by weight of the total weight of the block copolymer. Preferably the airtight elastomer layer also comprises, as a plasticizing agent, an extender oil for the SIBS elastomer. The inflatable article of the invention is, in particular, an inner tube or a pneumatic tire for a motor vehicle.

Abstract: A process for preparing a rare-earth organophosphate in the form of a gel that can be used as is for the preparation of a “preformed” catalyst system intended, in particular, for the cis-1,4 stereospecific polymerization of conjugated dienes.

Abstract: The present invention relates to a borohydride metallocene complex of a lanthanide, to its process of preparation, to a catalytic system incorporating it, to a process for the copolymerization of olefins employing this catalytic system and to an ethylene/butadiene copolymer obtained by this process, the butadiene units of which comprise 1,2-cyclohexane or 1,2- and 1,4-cyclohexane links.

Abstract: A borohydride metallocene complex of a lanthanide, its process of preparation, a catalytic system incorporating a borohydride metallocene complex and a process for the copolymerization of olefins employing this catalytic system.