A terpolymer of ethylene, of 1,3-butadiene and of an aromatic α-monoolefin is provided. The terpolymer contains more than 60 mol %, preferably at least 70 mol %, and preferably at most 90 mol % of ethylene units, at most 10 mol % of aromatic α-monoolefin units and 1,2-cyclohexanediyl units.

Such a diene terpolymer rich in ethylene units has the advantage of exhibiting a reduced, or even zero, crystallinity.

A method for producing a polydiene, the method comprising of combining a lanthanide compound, an alkylating agent, a halogen source, and optionally conjugated diene monomer to form an active preformed catalyst; independent of step (i), introducing an amine with conjugated diene monomer to be polymerized; independent of step (i), introducing the active preformed catalyst to the conjugated diene monomer to be polymerized to form an active polymerization mixture, where the active polymerization mixture includes less than 10% by weight, based on the total weight of the active polymerization mixture, of a solvent; and allowing the monomer to be polymerized to polymerize in the presence of the amine.

A method for producing a polydiene, the method comprising of combining a lanthanide compound, an alkylating agent, a halogen source, and optionally conjugated diene monomer to form an active preformed catalyst; independent of step (i), introducing an amine with conjugated diene monomer to be polymerized; independent of step (i), introducing the active preformed catalyst to the conjugated diene monomer to be polymerized to form an active polymerization mixture, where the active polymerization mixture includes less than 10% by weight, based on the total weight of the active polymerization mixture, of a solvent; and allowing the monomer to be polymerized to polymerize in the presence of the amine.

The polymerization catalyst composition includes: Component (A): a rare earth element compound of formula (i): M-(NQ.sup.1)(NQ.sup.2)(NQ.sup.3) (where M is at least one selected from lanthanoid, scandium, and yttrium, and NQ.sup.1, NQ.sup.2 and NQ.sup.3 are amide groups and each have a M-N bond; Component (B): a hydrocarbyl aluminoxane compound having a C1-20 hydrocarbon group; and Component (C): a compound of formula (X): YR.sup.1.sub.aR.sup.2.sub.bR.sup.3.sub.c (where Y is a metal selected from groups 1, 2, 12 and 13 in a periodic table, R.sup.1 and R.sup.2 are C1-10 hydrocarbon groups or hydrogen atoms and R.sup.3 is a C1-10 hydrocarbon group).

The polymerization catalyst composition includes: Component (A): a rare earth element compound of formula (i): M-(NQ.sup.1)(NQ.sup.2)(NQ.sup.3) (where M is at least one selected from lanthanoid, scandium, and yttrium, and NQ.sup.1, NQ.sup.2 and NQ.sup.3 are amide groups and each have a M-N bond; Component (B): a hydrocarbyl aluminoxane compound having a C1-20 hydrocarbon group; and Component (C): a compound of formula (X): YR.sup.1.sub.aR.sup.2.sub.bR.sup.3.sub.c (where Y is a metal selected from groups 1, 2, 12 and 13 in a periodic table, R.sup.1 and R.sup.2 are C1-10 hydrocarbon groups or hydrogen atoms and R.sup.3 is a C1-10 hydrocarbon group).

A process for the preparation of branched polybutadiene having a high content of 1,4-cis units which comprises polymerizing butadiene in the presence of at least one organic solvent, and in the presence of: a) a catalytic system prepared in situ including: (a.sub.1) at least one neodymium carboxylate, (a.sub.2) at least one alkyl compound of aluminum, (A.sub.3) at least one alkyl compound of aluminum containing at least one halogen atom, and b) at least one organic ester containing at least one halogen atom. Said branched polybutadiene having a high content of 1,4-cis units, depending on the branching degree and molecular weight distribution, can be advantageously used in various applications ranging from the modification of plastic materials [production, for example, of high impact polystyrene (HIPS)] to the production of tires, in particular the production of treads and/or of sidewalls of tires.

A process for the preparation of branched polybutadiene having a high content of 1,4-cis units which comprises polymerizing butadiene in the presence of at least one organic solvent, and in the presence of: a) a catalytic system prepared in situ including: (a.sub.1) at least one neodymium carboxylate, (a.sub.2) at least one alkyl compound of aluminum, (A.sub.3) at least one alkyl compound of aluminum containing at least one halogen atom, and b) at least one organic ester containing at least one halogen atom. Said branched polybutadiene having a high content of 1,4-cis units, depending on the branching degree and molecular weight distribution, can be advantageously used in various applications ranging from the modification of plastic materials [production, for example, of high impact polystyrene (HIPS)] to the production of tires, in particular the production of treads and/or of sidewalls of tires.

The present invention is directed to a functionalized elastomer comprising the reaction product of a living elastomeric polymer and a polymerization terminator of formula I, wherein the functionalized elastomer comprises repeat units of a diene monomer and optionally a vinyl aromatic monomer, and the functionalized elastomer comprises at least 92 percent by weight of cis 1,4 microstructure content based on the weight of the polydiene content of the functionalized elastomer ##STR00001##
wherein R.sup.1 is C1 to C4 linear alkyl, or C1 to C4 branched alkanediyl; X.sup.1, X.sup.2, X.sup.3 are independently O, S, or a group of formula (II) or (III) ##STR00002## ##STR00003##
where R.sup.2 is C1 to C18 linear or branched alkyl; Z is R.sup.3, —OR.sup.4, or —R.sup.5—X.sup.4; R.sup.3, R.sup.4 are independently C1 to C18 linear or branched alkyl; R.sup.5 is C1 to C18 alkanediyl or dialkyl ether diyl; X.sup.4 is halogen or a group of structure IV, V, VI, VII or VIII ##STR00004## ##STR00005## ##STR00006## ##STR00007## ##STR00008##
wherein R.sup.6, R.sup.7, R.sup.8, R.sup.9, and R.sup.10 are independently H or C1 to C8 alkyl; R.sup.11 is C2 to C8 alkanediyl; R.sup.12 and R.sup.13 are independently H, aryl or C1 to C8 alkyl;
Q is N or a group of structure IX ##STR00009##
wherein R.sup.14 is C1 to C8 alk.

The present invention is directed to a functionalized elastomer comprising the reaction product of a living elastomeric polymer and a polymerization terminator of formula I, wherein the functionalized elastomer comprises repeat units of a diene monomer and optionally a vinyl aromatic monomer, and the functionalized elastomer comprises at least 92 percent by weight of cis 1,4 microstructure content based on the weight of the polydiene content of the functionalized elastomer ##STR00001##
wherein R.sup.1 is C1 to C4 linear alkyl, or C1 to C4 branched alkanediyl; X.sup.1, X.sup.2, X.sup.3 are independently O, S, or a group of formula (II) or (III) ##STR00002## ##STR00003##
where R.sup.2 is C1 to C18 linear or branched alkyl; Z is R.sup.3, —OR.sup.4, or —R.sup.5—X.sup.4; R.sup.3, R.sup.4 are independently C1 to C18 linear or branched alkyl; R.sup.5 is C1 to C18 alkanediyl or dialkyl ether diyl; X.sup.4 is halogen or a group of structure IV, V, VI, VII or VIII ##STR00004## ##STR00005## ##STR00006## ##STR00007## ##STR00008##
wherein R.sup.6, R.sup.7, R.sup.8, R.sup.9, and R.sup.10 are independently H or C1 to C8 alkyl; R.sup.11 is C2 to C8 alkanediyl; R.sup.12 and R.sup.13 are independently H, aryl or C1 to C8 alkyl;
Q is N or a group of structure IX ##STR00009##
wherein R.sup.14 is C1 to C8 alk.

The cis-1,4 mer content of conjugated diene mer in polymers can be increased by adding any of a class of morpholine compounds to a catalyst composition that includes a lanthanide metal atom.