Compositions may comprise symmetrical and asymmetrical pyridine-containing transition metal-complexes having appended group 13 Lewis acids positioned on the pyridine-containing ligands of the transition metal-complex such that the group 13 Lewis acid may be near the catalytic site, thereby allowing the appended group 13 Lewis acid to function more efficiently in promoting formation of a catalytically active species. Catalysts systems may comprise these symmetrical and asymmetrical pyridine-containing transition metal-complexes and methods of preparing polyolefins may use these catalyst systems.

Compositions may comprise symmetrical and asymmetrical pyridine-containing transition metal-complexes having appended group 13 Lewis acids positioned on the pyridine-containing ligands of the transition metal-complex such that the group 13 Lewis acid may be near the catalytic site, thereby allowing the appended group 13 Lewis acid to function more efficiently in promoting formation of a catalytically active species. Catalysts systems may comprise these symmetrical and asymmetrical pyridine-containing transition metal-complexes and methods of preparing polyolefins may use these catalyst systems.

The invention relates to polybutadiene, which contains the monomer units derived from 1,3-butadiene having a vinyl double bond in a proportion of 25 to 75 mole percent, having a trans-double bond in a proportion of 0 to 10 mole percent and a cis-double bond in a proportion of 25 to 75 mole percent, wherein the totality of the monomer units (A), (B) and (C) is supplemented to 100 mole percent, and which is characterized in that it has a number-average mole mass of 1,000 to 3,000 g/mole. The invention further relates to a method for producing polybutadienes, the use of the polybutadiene according to the invention and compositions containing polybutadiene according to the invention.

The invention relates to polybutadiene, which contains the monomer units derived from 1,3-butadiene having a vinyl double bond in a proportion of 25 to 75 mole percent, having a trans-double bond in a proportion of 0 to 10 mole percent and a cis-double bond in a proportion of 25 to 75 mole percent, wherein the totality of the monomer units (A), (B) and (C) is supplemented to 100 mole percent, and which is characterized in that it has a number-average mole mass of 1,000 to 3,000 g/mole. The invention further relates to a method for producing polybutadienes, the use of the polybutadiene according to the invention and compositions containing polybutadiene according to the invention.

A block copolymer is disclosed. The block copolymer has a structure of formula (V) below:

[D].sub.x-[E].sub.y-[F].sub.z  (V) wherein D, E, and F are each independently a compound of formula (VI) below, and D, E, and F are different from each other; and x, y, and z are each independently an integer from 1 to 40;

##STR00001## wherein A.sub.2 is O or S; R.sub.7 is H or a C.sub.1-6 alkyl; and R.sub.8 is a C.sub.1-12 alkyl, (CH.sub.2).sub.qN(R.sub.11).sub.2, CH.sub.2(CH.sub.2OCH.sub.2).sub.rCH.sub.2N(R.sub.12).sub.2, or CH.sub.2(CH.sub.2OCH.sub.2).sub.sCH.sub.2OR.sub.13, wherein R.sub.11, R.sub.12, and R.sub.13 are each independently a C.sub.1-6 alkyl; and q, r, and s are each independently an integer from 1 to 10.

A polybutadiene composition which enables the achievement of a rubber material that has excellent crack propagation resistance and a method for producing this polybutadiene composition are provided. A polybutadiene composition is produced by a method that comprises a step Y wherein 1,3-butadiene is polymerized in the presence of 1,2-polybutadiene and a lanthanoid catalyst. A polybutadiene composition which contains 1,2-polybutadiene and 1,4-polybutadiene, and which is obtained by polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanoid catalyst.

A polybutadiene composition which enables the achievement of a rubber material that has excellent crack propagation resistance and a method for producing this polybutadiene composition are provided. A polybutadiene composition is produced by a method that comprises a step Y wherein 1,3-butadiene is polymerized in the presence of 1,2-polybutadiene and a lanthanoid catalyst. A polybutadiene composition which contains 1,2-polybutadiene and 1,4-polybutadiene, and which is obtained by polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanoid catalyst.

The present invention provides a method for preparing a transition metal complex, including a step of preparing a dispersion including a transition metal salt or alkoxide, and a coordinating solvent; and a step of reacting an organic borate-based compound containing a carbon-based, silyl-based or amine-based cation and a borate-based bulky anion, with the dispersion, wherein the transition metal is one or more selected from the metals in group 7 to group 12.

The present invention provides a method for preparing a transition metal complex, including a step of preparing a dispersion including a transition metal salt or alkoxide, and a coordinating solvent; and a step of reacting an organic borate-based compound containing a carbon-based, silyl-based or amine-based cation and a borate-based bulky anion, with the dispersion, wherein the transition metal is one or more selected from the metals in group 7 to group 12.

A block copolymer and a method for preparing the same are disclosed. The method comprises the following steps: (A) mixing a compound of formula (I), a catalyst of formula (II), and a first solvent to obtain a first mixture; (B) adding a first monomer into the first mixture for reaction to obtain a second mixture; and (C) adding a second monomer into the second mixture for reaction to obtain a third mixture; wherein the compound of formula (I) and the catalyst of formula (II) are as defined in the specification.