Abstract: Branched crystalline polypropylene compositions and methods for the preparation of branched crystalline polypropylene compositions are provided. For example, described herein is a process of preparing a branched crystalline polypropylene composition that includes combining two or more different metallocene catalyst compounds with a polymerization medium that includes propylene, for a time sufficient to provide branched crystalline polypropylene that has from 0.0 wt % to 2.0 wt % ethylene and a heat of fusion of 70 J/g or more.

Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization. The metallocene compositions may be represented by the formula: wherein R3 are identical or different and are each a halogen atom, a C1-C10 alkyl group which may be halogenated, a C6-C10 aryl group which may be halogenated, a C2-C10 alkenyl group, a C7-C40-arylalkyl group, a C7-C40 alkylaryl group, a C8-C40 arylalkenyl group, a —NR?2, —SR?, —OR?, —OSiR?3 or —PR?2 radical, wherein R? is one of a halogen atom, a C1-C10 alkyl group, or a C6-C10 aryl group, and R9 and R11 are identical or different and are a Group 14 radical having from 1 to 20 carbon atoms or are each primary, secondary or tertiary butyl groups, aryl groups, isopropyl groups, fluoroalkyl groups, trialkyl silyl groups, or other groups of similar size.

Abstract: Branched crystalline polypropylene compositions and methods for the preparation of branched crystalline polypropylene compositions are provided. For example, described herein is a process of preparing a branched crystalline polypropylene composition that includes combining two or more different metallocene catalyst compounds with a polymerization medium that includes propylene, for a time sufficient to provide branched crystalline polypropylene that has from 0.0 wt % to 2.0 wt % ethylene and a heat of fusion of 70 J/g or more.

Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization.

Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization.

Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization.

Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization.

Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization.

Abstract: This invention relates to a catalyst system comprising a substituted, bridged bisindenyl metallocene supported on a polymeric support wherein the metallocene is activated for polymerization by an ionizing reaction and stabilized in cationic form with a noncoordinating anion. A protonated ammonium salt of a noncoordinating amine is covalently bonded to the support. Propylene polymers produced by these supported catalyst systems have melting points and polymer microstructures similar to propylene polymers produced using analogous unsupported catalyst systems.

Abstract: This invention relates to supported metallocene catalyst compositions useful for addition reactions of prochiral .alpha.-olefins. Polymers, specifically propylene polymers, produced with this catalyst possess higher stereoregularities and consequently higher melting points compared to propylene polymers produced using previously known supported metallocene catalysts. The microstructure of the polymers obtained using the supported catalyst systems of this invention is similar to that obtained using analogous unsupported catalysts. The catalyst compositions comprise transition metal (i.e., metallocene) cations and beam comprising anionic activators in prescribed ratios on metal or metalloid oxide supports. The transition metal compound is represented by the formula: ##STR1## wherein M is selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten;R.sup.1 and R.sup.2 are identical or different, and are one of a hydrogen atom, a C.sub.1 -C.