Abstract: Process for the preparation of a diene polymer or a random vinyl arene-diene copolymer comprising anionically (co)polymerizing at least one conjugated diene monomer, optionally in the presence of at least one vinyl arene, in the presence of at least one hydrocarbon solvent, at least one lithium-based initiator and at least one organic compound containing at least one nitrox- ide group having general formula (I) or (II): wherein: R1, R2, R3 and R4, mutually identical or different, represent a hydrogen atom; or are selected from C1-C20, preferably C1-C8, linear or branched alkyl groups optionally containing heteroatoms such as, for example, oxygen, nitrogen, sulphur, optionally substituted cycloalkyl groups, optionally substituted C1-C20, preferably C1-C8, linear or branched alkoxy groups, optionally substituted aryl groups; -x is an integer ranging from 0 to 7, preferably ranging from 4 to 5; -y is an integer ranging from 1 to 3, preferably ranging from 1 to 2.

Abstract: Process for the preparation of a diene polymer or a random vinyl arene-diene copolymer comprising anionically (co)polymerising at least one conjugated diene monomer, optionally in the presence of at least one vinyl arene, in the presence of at least one hydrocarbon solvent, at least one lithium-based initiator and at least one organic compound containing at least one nitroxide group having general formula (I) or (II): wherein: R1, R2, R3 and R4, mutually identical or different, represent a hydrogen atom; or are selected from C1-C20, preferably C1-C8, linear or branched alkyl groups optionally containing heteroatoms such as, for example, oxygen, nitrogen,sulphur,optionally substituted cycloalkyl groups, optionally substituted C1-C20, preferably C1-C8, linear or branched alkoxy groups, optionally substituted aryl groups; ?x is an integer ranging from 0 to 7, preferably ranging from 4 to 5; ?y is an integer ranging from 1 to 3, preferably ranging from 1 to 2.

Abstract: A process for the preparation of a functionalized and branched elastomeric copolymer comprising the following steps: (a) anionic copolymerization of at least one conjugated diene monomer and at least one vinyl arene, in the presence of at least one hydrocarbon solvent, of at least one lithium-based initiator, and of at least one polar modifier, obtaining a solution comprising an elastomeric copolymer; (b) reacting at least 10% by weight, preferably from 20% by weight to 100 % by weight, of the polymeric chains present in the elastomeric copolymer obtained in step (a) with at least one compound having at least one functional group selected from: epoxides, ketones, esters, aldehydes, obtaining a solution comprising a functionalized elastomeric copolymer; (c) adding a quantity of lithium-based initiator to the solution obtained in step (b), from 1 to 4 times, preferably from 1.

Abstract: Process for the preparation of diene polymers or random vinyl arene-diene copolymers which comprises (co)polymerizing, anionically, in the presence of at least one hydrocarbon solvent, at least one conjugated diene monomer and optionally at least one vinyl arene, in the presence of at least one lithium-based initiator, at least one aprotic polar compound, and at least one compound containing one or more functional groups of the acetylenic type. Said process allows diene polymers or random vinyl arene-diene copolymers to be obtained, which can be advantageously used in the production of tires, in particular in the production of tire treads. The diene polymers or the random vinyl arene-diene copolymers obtained through said process can also be used for the modification of plastic materials [for example, for obtaining high impact polystyrene (HIPS)].

Abstract: A process for the preparation of a 1,3-butadiene and styrene copolymer comprising the following steps: a) anionically polymerizing a blend comprising from 5% by weight to 40% by weight of styrene and from 60% by weight to 95% by weight of 1,3-butadiene, with respect to the overall weight of the mixture, in the presence of at least one hydrocarbon solvent, of at least one lithium-based catalyst having the general formula LiR1 wherein R1 represents a linear or branched C3-C10 alkyl group, and of least one polar modifier; b) optionally, reacting the copolymer obtained in step (a) with at least one chain-end monomer selected from 1,3-butadiene, styrene and ?-methylstyrene; c) reacting from 10% by weight to 70% by weight, preferably from 20% by weight to 50% by weight, of the lithium-terminated polymeric chains present in the copolymer obtained in step (a) or in step (b), with at least one coupling agent selected from liquid polyepoxides having at least three reactive sites capable of reacting with the carbon-lith

Abstract: Process for the preparation of diene polymers or random vinyl arene-diene copolymers which comprises (co) polymerizing, anionically, in the presence of at least one hydrocarbon solvent, at least one conjugated diene monomer and optionally at least one vinyl arene, in the presence of at least one lithium-based initiator, at least one aprotic polar compound, and at least one compound containing one or more functional groups of the acetylenic type. Said process allows diene polymers or random vinyl arene-diene copolymers to be obtained, which can be advantageously used in the production of tyres, in particular in the production of tyre treads. The diene polymers or the random vinyl arene-diene copolymers obtained through said process can also be used for the modification of plastic materials [for example, for obtaining high impact polystyrene (HIPS)].

Abstract: A process for the preparation of a functionalized and branched elastomeric copolymer comprising the following steps: (a) anionic copolymerization of at least one conjugated diene monomer and at least one vinyl arene, in the presence of at least one hydrocarbon solvent, of at least one lithium-based initiator, and of at least one polar modifier, obtaining a solution comprising an elastomeric copolymer; (b) reacting at least 10% by weight, preferably from 20% by weight to 100% by weight, of the polymeric chains present in the elastomeric copolymer obtained in step (a) with at least one compound having at least one functional group selected from: epoxides, ketones, esters, aldehydes, obtaining a solution comprising a functionalized elastomeric copolymer; (c) adding a quantity of lithium-based initiator to the solution obtained in step (b), from 1 to 4 times, preferably from 1.

Abstract: A process for the preparation of a 1,3-butadiene and styrene copolymer comprising the following steps: a) anionically polymerizing a blend comprising from 5% by weight to 40% by weight of styrene and from 60% by weight to 95% by weight of 1,3-butadiene, with respect to the overall weight of the mixture, in the presence of at least one hydrocarbon solvent, of at least one lithium-based catalyst having the general formula LiR1 wherein R1 represents a linear or branched C3-C10 alkyl group, and of least one polar modifier; b) optionally, reacting the copolymer obtained in step (a) with at least one chain-end monomer selected from 1,3-butadiene, styrene and ?-methylstyrene; c) reacting from 10% by weight to 70% by weight, preferably from 20% by weight to 50% by weight, of the lithium-terminated polymeric chains present in the copolymer obtained in step (a) or in step (b), with at least one coupling agent selected from liquid polyepoxides having at least three reactive sites capable of reacting with the carbon-lith

Abstract: A process for the preparation of diene polymers or vinylarene-diene statistical (random) copolymers which comprises the anionic (cp) polymerization, in hydrocarbon solvents, of at least one monomer of a conjugated diene, optionally in the presence of a vinyl aryl monomer, and using a compound belonging to the group of lithium alkyls as initiator, characterized in that the total lithium alkyl initiator is modified in situ by means of a reaction with a compound having general formula (I): Rm—(X—H)n (I) wherein R is a C2-C20 (cyclo) alkyl or C6-C20 aromatic radical, X is a heteroatom belonging to group VA or group VIA of the periodic system, n is an integer higher than or equal to 1, m is an integer>1 which depends on the valence of the heteroatom X.

Abstract: A process for the preparation of diene polymers or vinylarene-diene statistical (random) copolymers which comprises the anionic (cp) polymerization, in hydrocarbon solvents, of at least one monomer of a conjugated diene, optionally in the presence of a vinyl aryl monomer, and using a compound belonging to the group of lithium alkyls as initiator, characterized in that the total lithium alkyl initiator is modified in situ by means of a reaction with a compound having general formula (I): Rm—(X—H)n (I) wherein R is a C2-C20 (cyclo) alkyl or C6-C20 aromatic radical, X is a heteroatom belonging to group VA or group VIA of the periodic system, n is an integer higher than or equal to 1, m is an integer>1 which depends on the valence of the heteroatom X.

Abstract: A raw elastomeric composition includes: (a1) from 30 to 90% by weight of a partially hydrogenated vinylarene-conjugated diene random elastomeric copolymer; (a2) from 10 to 70% by weight of one or more diene rubbers; (b) from 10 to 150 phr of silica; (c) from 0.1 to 20 phr of a coupling agent based on silane; (d) from 0.1 to 10 phr of a vulcanization agent; wherein the partially hydrogenated vinylarene-conjugated diene random copolymer has a structure which has nodes statistically distributed in the macromolecule, from which polymeric chains branch out, the bond between the nodes and the branches being a carbon-carbon bond.

Abstract: Vinyl aromatic (co) polymer reinforced with a rubber selected from a linear diene rubber (i) with a solution viscosity lower than 70 cPs; a partially radial diene rubber (ii), with a solution viscosity lower than 70 cPs; a three-chain diene rubber (iii) with a solution viscosity lower than 70 cPs; a blend of linear diene rubbers (i) and radial diene rubbers (iv) in a maximum ratio between them (i)/(iv) of between 99.5/0.5 and 85/15.

Abstract: Process for the partial hydrogenation of random vinyl arene-conjugated diene copolymers in the presence of 2-methoxyethyl tetrahydrofuran as randomizing agent, comprising: reacting the random vinyl arene-conjugated diene copolymer, dissolved in a hydrocarbon solvent, with hydrogen, in the presence of a titanium complex and an alkylating agent, until the desired hydrogenation degree is obtained the above process being characterized in that the alkylating agent is selected from compounds having the general formula MgR1R2

Abstract: A raw elastomeric composition includes: (a1) from 30 to 90% by weight of a partially hydrogenated vinylarene-conjugated diene random elastomeric copolymer; (a2) from 10 to 70% by weight of one or more diene rubbers; (b) from 10 to 150 phr of silica; (c) from 0.1 to 20 phr of a coupling agent based on silane; (d) from 0.1 to 10 phr of a vulcanization agent; wherein the partially hydrogenated vinylarene-conjugated diene random copolymer has a structure which has nodes statistically distributed in the macromolecule, from which polymeric chains branch out, the bond between the nodes and the branches being a carbon-carbon bond.

Abstract: Process for the production of statistic elastomeric conjugated diene-vinyl arene copolymers having a branched structure which comprises: (1) anionic copolymerization in solution of the conjugated diene and vinyl arene monomers, in the presence of randomizing agents and an initiator selected from the group of Lithium alkyls, the copolymerization being carried out until the almost total disappearance of the monomers; (2) addition to the solution of step (1) of a quantity of Lithium alkyl from 1 to 4 times the molar quantity of the Lithium alkyl of step (1); (3) addition to the polymeric solution of step (2) of a compound having the general formula R—Br, the molar ratio between R—Br and the total Lithium alkyl ranging from 0.6/1 to 1/1, preferably from 0.7/1 to 0.9/1, thus obtaining an elastomeric branched copolymer.

Abstract: Process for the production of statistic elastomeric conjugated diene-vinyl arene copolymers having a branched structure which comprises: (1) anionic copolymerization in solution of the conjugated diene and vinyl arene monomers, in the presence of randomizing agents and an initiator selected from the group of Lithium alkyls, the copolymerization being carried out until the almost total disappearance of the monomers; (2) addition to the solution of step (1) of a quantity of Lithium alkyl from 1 to 4 times the molar quantity of the Lithium alkyl of step (1); (3) addition to the polymeric solution of step (2) of a compound having the general formula R—Br, the molar ratio between R—Br and the total Lithium alkyl ranging from 0.6/1 to 1/1, preferably from 0.7/1 to 0.9/1, thus obtaining an elastomeric branched copolymer.