Abstract: The disclosed invention relates to a polymerization process comprising contacting ethylene, and optionally, one or more olefinically unsaturated comonomers, with an active supported Group 3, 4, 5, or 6 metallocene catalyst system having an unsubstituted or substituted fused-ring cyclopentadienyl ligand, preferably indenyl or fluorenyl, and a substituted or unsubstituted cyclopentadienyl ligand under gas-phase or slurry polymerization conditions. The process is suitable for the production of high-density polyethylene homopolymers and copolymers. The benefits to industrial practice are both the ease of preparation and low-cost of the precursor metallocene compound and the commercially feasible polymerization activity levels in stable, low fouling level reactor conditions surprisingly associated with it. Additionally, the polymers made under the invention process conditions have narrow molecular weight distributions, low MI, and low values for MIR.

Abstract: Blends of semi-crystalline polymers with rubbery thermoplastic copolymers are provided. The rubbery thermoplastic copolymers are elastic at temperatures above their Tg's and properties similar to thermoplastic elastomers and surface tensions 5 dynes/cm or more different, preferably greater than the surface tension of the semi-crystalline polymer. Improved properties include good elastic recovery, toughness, and high elasticity without significant loss in optical properties.

Abstract: This invention is a solution process for the preparation of ethylene-.alpha.-olefin/diolefin copolymers comprising contacting ethylene, one or more .alpha.-olefin monomer, and optionally one or more diene monomer, with a catalyst system containing a catalyst activator and a Group 4 metallocene compound, comprising a) conducting the polymerization reaction at a temperature of about 60.degree. to 150.degree. C.; b) selecting as the Group 4 metallocene compound one or more members of the group consisting of cyclic monocyclopentadienyl Group 4 metal and covalently bridged (bis)indenyl hafnium metallocene compounds; and c) maintaining the .alpha.-olefin concentration at a molar ratio to that of ethylene of between about 0.3 to 7.0 and a diolefin to ethylene molar ratio of between about 0.01 and 0.4. In a preferred embodiment the process comprises: 1) mixing with a reaction solvent the one or more .alpha.