Abstract: A copolymer of ethylene and of myrcene, in which the ethylene units represent between 50 mol % and 95 mol % of the ethylene units and of the myrcene units, and the myrcene units of 1,2 and 3,4 configuration represent more than 50 mol % of the myrcene units, is provided. Such a copolymer exhibits an improved compromise between the degree of crystallinity and the stiffness. It therefore makes it possible to widen the field of application of ethylene-rich diene copolymers in rubber compositions, and also to increase the production capacity of a unit for the synthesis of ethylene-rich diene polymers.

Abstract: A catalytic system based at least on a preformation conjugated diene monomer, on an organometallic compound as cocatalyst and on a metallocene of formula {P(Cp1)(Cp2)Y} is provided. In the formula, Y denotes a group comprising a metal atom which is a rare earth metal, Cp1 and Cp2, which are identical or different, are selected from the group consisting of fluorenyl groups, cyclopentadienyl groups and indenyl groups, the groups being substituted or unsubstituted, and P is a group bridging the two Cp1 and Cp2 groups and comprising a silicon or carbon atom. Such a catalytic system exhibits an improved stability of the catalytic activity over time, in particular on storage.

Abstract: A copolymer of a 1,3-diene and of an olefin selected from the group consisting of ?-monoolefins, ethylene and mixtures thereof is provided. The copolymer bears, at one of its chain ends, an alkoxysilyl or silanol function, functional group F1, and the copolymer is different from a copolymer of a 1,3-diene and a vinylaromatic monomer.

Abstract: An ethylene/1,3-butadiene copolymer containing ethylene units, butadiene units and UD units of cyclic, 1,2-cyclohexanediyl structure, and bearing, at one of its chain ends, an alkoxysilyl or silanol function, functional group F1 is provided.

Abstract: Methods for producing phloroglucinol as well as methods of using type III polyketide synthases as phloroglucinol synthases, in particular the type III polyketide synthases of algae, such as eukaryotic ochrophyte algae, are described herein. In addition, polypeptides that have phloroglucinol synthase activity, the isolated nucleic acid molecules encoding these type III polyketide synthases, and the vectors and the host cells comprising such nucleic acid molecules are also described.

Abstract: A catalytic system based at least on a preformation monomer selected from the group consisting of 1,3-dienes, ethylene, ?-monoolefins and their mixtures, on a metallocene of formula {P(Cp)(Flu)LnG} and on an organometallic compound as cocatalyst is provided. In the formula, Ln denotes a metal atom which is a rare earth metal, G denotes a group comprising the borohydride BH4 unit or denotes a halogen atom X selected from the group consisting of chlorine, fluorine, bromine and iodine, Cp denotes a cyclopentadienyl group of formula C5H4, Flu denotes a fluorenyl group of formula C13H8, P being a group bridging the two Cp and Flu groups and comprising a silicon or carbon atom. Such a catalytic system exhibits an improved stability of the catalytic activity over time, in particular on storage.

Abstract: A catalytic system based at least on a preformation monomer which is ethylene or a mixture of ethylene and of a conjugated diene, on a metallocene of formula {P(Cp1)(Cp2)Y} or Cp3Cp4Y and on an organometallic compound as cocatalyst, Y denoting a group comprising a metal atom which is a rare earth metal, the Cp1, Cp2, Cp3 and Cp4 groups, which are identical or different, being selected from the group consisting of fluorenyl groups, cyclopentadienyl groups and indenyl groups, the groups being substituted or unsubstituted, and P being a group bridging the two Cp1 and Cp2 groups and comprising a silicon or carbon atom, is provided. Such a catalytic system exhibits an improved stability of the catalytic activity over time, in particular on storage.

Abstract: A one-pot process for preparing a preformed catalytic system based on a rare-earth metallocene in a hydrocarbon solvent in three performed steps.

Abstract: A catalytic system based at least on isoprene as preformation monomer, on a metallocene of formula {P(Cp1)(Cp2)Y} and on an organometallic compound as cocatalyst, Y denoting a group comprising a metal atom which is a rare earth metal, Cp1 and Cp2, which are identical or different, being selected from the group consisting of fluorenyl groups, cyclopentadienyl groups and indenyl groups, the groups being substituted or unsubstituted, and P being a group bridging the two Cp1 and Cp2 groups and comprising a silicon or carbon atom, is provided. Such a catalytic system is soluble and exhibits an increased stability of the catalytic activity over time, in particular on storage.

Abstract: A catalytic system based at least on a preformation conjugated diene monomer, on an organometallic compound as cocatalyst and on a metallocene of formula {P(Cp1)(Cp2)Y} is provided. In the formula, Y denotes a group comprising a metal atom which is a rare earth metal, Cp1 and Cp2, which are identical or different, are selected from the group consisting of fluorenyl groups, cyclopentadienyl groups and indenyl groups, the groups being substituted or unsubstituted, and P is a group bridging the two Cp1 and Cp2 groups and comprising a silicon or carbon atom. Such a catalytic system exhibits an improved stability of the catalytic activity over time, in particular on storage.