Abstract: A catalytic system usable for the copolymerization of at least one conjugated diene and at least one monoolefin, a process for preparing this catalytic system, a process for preparing a copolymer of a conjugated diene and at least one monoolefin using said catalytic system, and said copolymer are described.

Abstract: Disclosed are ethylene and butadiene copolymers and a catalytic system usable for the synthesis of these copolymers. The copolymers have a molar content of units resulting from butadiene of ?8%, said units comprising trans-1,2 cyclohexane linkages, and a number-average molecular mass Mn of ?40,000 g/mol. The catalytic system includes: (i) an organometallic complex represented by one of the following formulae A or B: where Ln represents a lanthanide and X a halogen, where, in the formula A, two ligand molecules Cp1 and Cp2 each consisting of a fluorenyl group, are attached to Ln, where, in the formula B, a ligand molecule consisting of two fluorenyl groups Cp1 and Cp2, joined together by a bridge P of formula MR2, where M is an element of column IVa and R is an alkyl with 1 to 20 carbon atoms, is attached to Ln, and (ii) a co-catalyst selected from an alkylmagnesium, an alkyllithium, an alkylaluminium, a Grignard reagent, or a mixture of these constituents.

Abstract: A catalytic system usable for the copolymerization of at least one conjugated diene and at least one monoolefin, a process for preparing this catalytic system, a process for preparing a copolymer of a conjugated diene and at least one monoolefin using said catalytic system, and said copolymer are described.

Abstract: Disclosed are ethylene and butadiene copolymers and a catalytic system usable for the synthesis of these copolymers. The copolymers have a molar content of units resulting from butadiene of ?8%, said units comprising trans-1,2 cyclohexane linkages, and a number-average molecular mass Mn of ?40,000 g/mol. The catalytic system includes: (i) an organometallic complex represented by one of the following formulae A or B: where Ln represents a lanthanide and X a halogen, where, in the formula A, two ligand molecules Cp1 and Cp2 each consisting of a fluorenyl group, are attached to Ln, where, in the formula B, a ligand molecule consisting of two fluorenyl groups Cp1 and Cp2, joined together by a bridge P of formula MR2, where M is an element of column IVa and R is an alkyl with 1 to 20 carbon atoms, is attached to Ln, and (ii) a co-catalyst selected from an alkylmagnesium, an alkyllithium, an alkylaluminium, a Grignard reagent, or a mixture of these constituents.