摘要:
A compound and the use thereof to prepare a functional or telechelic polyolefin is provided. The compound has the following formula (II): Y((CH2)p—B′)m (II), wherein m=2 or 3; Y being an alkaline earth metal or zinc when m=2, Y being aluminum when m=3; B′ being selected from the group comprising N(SiMe3)2; N(SiMe2CH2CH2SiMe2); C6F5; C3F7; C6F13; para-C6H4—NMe2; para-C6H4—O-Me; para-C6H4—N(SiMe3)2; and CH(OCH2CH2O); and p being an integer from 0 to 50.
摘要:
The present invention relates to a novel catalytic system for polymerization, and more particularly for preparing conjugated diene polymers bearing a polar function at the chain end. This catalytic system is based on a metal salt of a rare-earth metal and, as alkylating agent, an organometallic compound based on a metal belonging to the 2nd column or the 13th column of the Periodic Table, capable of transferring a polar function to the diene elastomer during the conjugated diene polymerization step. The novel catalytic system makes it possible to reduce the steps for synthesizing a chain-end functionalized elastomer, while ensuring optimal functionalization, advantageously close or equal to 100%.
摘要:
The present invention relates to a novel catalytic system for polymerization, and more particularly for preparing conjugated diene polymers bearing a polar function at the chain end. This catalytic system is based on a metal salt of a rare-earth metal and, as alkylating agent, an organometallic compound based on a metal belonging to the 2nd column or the 13th column of the Periodic Table, capable of transferring a polar function to the diene elastomer during the conjugated diene polymerization step. The novel catalytic system makes it possible to reduce the steps for synthesizing a chain-end functionalized elastomer, while ensuring optimal functionalization, advantageously close or equal to 100%.
摘要:
The present invention relates to a rubber composition based on a reinforcing filler and on an elastomer matrix comprising a highly saturated diene elastomer comprising at least five distinct units of A, B, C, D and E distributed randomly within the elastomer at respective molar fractions of m %, n %, o %, p % and q %, where m+n+o+p+q=100; m≥50; n+o+p+q≥10; and 15≥p+q≥2.This rubber composition enables a satisfactory degree of stiffness to be reached while maintaining hysteresis properties acceptable for use in the manufacture of tires for running vehicles.
摘要:
A rubber composition based on a reinforcing filler and on an elastomeric matrix comprising a highly saturated diene elastomer, comprising units of the following categories A, B, C, D and E, or units of these same categories A, B, C, D and E comprising, for at least one of the categories B, C, D and E, a mixture of at least two different units of the same category which differ from one another through the nature of their side groups Ri: and where R1, R2, R3 and R4, which are identical or different, denote a hydrogen atom, a methyl radical or a phenyl radical which is substituted or unsubstituted in the ortho, meta or para position by a methyl radical; R5 denotes a hydrogen atom or a methyl radical; R6 denotes a methyl radical or a phenyl radical which is substituted or unsubstituted in the ortho, meta or para position by a methyl radical; m, n, o, p and q are numbers ranging from 0 to 100. This rubber composition enables a satisfactory degree of stiffness to be achieved while maintaining acceptable hysteresis properties, or even improving them, for use in the manufacture of tires for motor vehicles.
摘要:
A polymer comprises randomly distributed units UA, UB, UC and UD and at least one unit bearing a subunit F according to the respective molar percentages m, n, o, p and f F pendant along the chain of the polymer and bearing an associative group comprising at least one nitrogen atom, R1 and R2, which are identical or different, denoting a hydrogen atom, a methyl radical or a phenyl radical which is unsubstituted or substituted in the ortho, meta or para position by a methyl radical, m≥50, n≥0, o≥0, f>0, 0
摘要:
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.
摘要:
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.
摘要:
The present invention relates to comb block copolymers, combining an elastomeric backbone and rigid pendent blocks and thus having thermoplastic elastomer properties. The invention targets in particular comb block copolymers which may be used as a material as is.According to the invention, the comb block copolymer is a diene/polypropylene thermoplastic elastomer copolymer, characterized in that it consists of a backbone, said backbone being derived from a diene elastomer, and in that it comprises from 5% to 50% by weight, relative to the total weight of the copolymer, of pendent semicrystalline polypropylene groups distributed along the backbone.Another subject of the invention is the process for preparing same, and the compositions comprising same.Finally, a subject of the invention is a tire, one of the constituent elements of which comprises such a composition.
摘要:
A process for the synthesis of an ethylene/butadiene copolymer is provided. The process is continuous and comprises the following steps: a. feeding at least one stirred polymerization reactor with a mixture of ethylene, butadiene, hydrocarbon-based solvent and catalytic system allowing the formation of cyclic trans-1,2-cyclohexane units in the polymer chain with a mole ratio of ethylene to the sum of the ethylene and butadiene monomers ranging from 0.5 to 0.99; the concentration of ethylene and butadiene monomers in the polymerization reaction medium being less than 15% by weight; the operating pressure of the reactor is greater than or equal to the saturated vapour pressure of the polymerization reaction medium; and the polymerization temperature is greater than 90° C.; b. recovering the ethylene/butadiene copolymer, this copolymer comprising, statistically distributed, ethylene units, butadiene units and trans-1,2-cyclohexane units, the molar fraction of ethylene units in the copolymer being greater than or equal to 50%.