The present invention provides 1,4-cis polybutadiene having high linearity with an S/R value of 1 or greater at 100 C., and accordingly, is capable of reducing resistance properties, particularly rolling resistance, and greatly enhancing fuel efficiency properties when used in a rubber composition.

The present invention provides 1,4-cis polybutadiene having high linearity with an S/R value of 1 or greater at 100 C., and accordingly, is capable of reducing resistance properties, particularly rolling resistance, and greatly enhancing fuel efficiency properties when used in a rubber composition.

The present invention provides polymers and methods of preparing the same. In certain embodiments, the polymers comprise acrylate repeating units that have been derivatized (e.g., reduced and/or substituted) to form new polymeric structures. In certain embodiments, the polymers described herein self-assemble to form well-defined nanostructures. In some instances, the nanostructures exhibit relatively small d-spacing (e.g., a d-spacing value of 10 nm or less). Due to their properties, the polymers described herein are useful in a variety of applications including functional materials and biomedical applications.

The present invention provides polymers and methods of preparing the same. In certain embodiments, the polymers comprise acrylate repeating units that have been derivatized (e.g., reduced and/or substituted) to form new polymeric structures. In certain embodiments, the polymers described herein self-assemble to form well-defined nanostructures. In some instances, the nanostructures exhibit relatively small d-spacing (e.g., a d-spacing value of 10 nm or less). Due to their properties, the polymers described herein are useful in a variety of applications including functional materials and biomedical applications.

A process may include contacting ethylene monomer with Ziegler-Natta catalyst to form polyethylene. The Ziegler-Natta catalyst may be formed by contacting an alkyl magnesium compound with an alcohol and a metal reagent to form a blend, and contacting the blend with a first agent to form a solution of reaction product A. The solution of reaction product A may be contacted with a second agent to form a solid reaction product B, and the solid reaction product B may be contacted with a third agent to form a solid reaction product C. The solid reaction product C may be contacted with a fourth agent to form a solid reaction product D, and the solid reaction product D may be contacted with a fifth agent to form a catalyst component.

Olefin polymerization catalyst systems and methods for making and using the same are provided.

Olefin polymerization catalyst systems and methods for making and using the same are provided.

A bis-imine pyridine complex of lanthanides having general formula (I):

##STR00001## Said bis-imine pyridine complex of lanthanides having general formula (I) can be advantageously used in a catalytic system for the (co)polymerization of conjugated dienes.

Catalyst component for the polymerization of olefins comprising Mg, Ti and an electron donor of formula (I) ##STR00001##
Where R.sub.1 and R.sub.2, independently, are selected from hydrogen and C.sub.1-C.sub.15 hydrocarbon groups, optionally contain an heteroatom selected from halogen, P, S, N, O and Si, which can be fused together to form one or more closed cycles and A is a bivalent bridging group.

Silica-coated alumina activator-supports, and catalyst compositions containing these activator-supports, are disclosed. Methods also are provided for preparing silica-coated alumina activator-supports, for preparing catalyst compositions, and for using the catalyst compositions to polymerize olefins.