A method of polymerizing olefins is disclosed. The method comprises contacting ethylene and at least one comonomer with a catalyst system to produce a polyolefin polymer that is multimodal. The catalyst system comprises a first catalyst that promotes polymerization of the ethylene into a low molecular weight (LMW) portion of the polyolefin polymer and a second catalyst that promotes polymerization of the ethylene into a high molecular weight (HMW) portion of the polyolefin polymer. The first catalyst and at least a portion of the second catalyst are co-supported to form a commonly-supported catalyst system and at least a portion of the second catalyst is added as a catalyst trim feed to the catalyst system.

Catalyst systems and methods for making and using the same are described. A method includes selecting a catalyst blend using a blend polydispersity index (bPDI) map. The polydispersity map is generated by generating a number of polymers for at least two catalysts. Each polymer is generated at a different hydrogen to ethylene ratio. At least one catalyst generates a higher molecular weight polymer and another catalyst generates a lower molecular weight polymer. A molecular weight for each polymer is measured. The relationship between the molecular weight of the polymers generated by each of the catalysts and the ratio of hydrogen to ethylene is determined. A family of bPDI curves for polymers that would be made using a number of ratios of a blend of the at least two catalysts for each of a number of ratios of hydrogen to ethylene. A ratio for the catalyst blend of the catalysts that generates a polymer having a bPDI that matches a polymer fabrication process is selected, and the product specific polyolefin is made using the catalyst blend.

Polymers, and systems and methods for making and using the same are described herein. A polymer includes ethylene and at least one alpha olefin having from 4 to 20 carbon atoms. The polymer has a melt index ratio (MIR) greater than about 40. The polymer also has a value for Mw1/Mw2 of at least about 2.0, wherein Mw1/Mw2 is a ratio of a weight average molecular weight (Mw) for a first half of a temperature rising elution (TREF) curve from a cross-fractionation (CFC) analysis to an Mw for a second half of the TREF curve. The polymer also has a value for Tw1Tw2 of less than about 15 C., wherein Tw1Tw2 is a difference of a weight average elution temperature (Tw) for the first half of the TREF curve to a Tw for the second half of the TREF curve.

Disclosed are biaxially stretched polyolefin films containing 10 to 45% by weight of a cycloolefin polymer with a glass transition temperature between 12 and 170 C., and 90 to 55% by weight of a semi-crystalline alpha-olefin polymer with a crystallite melting temperature between 15 and 170 C. The glass transition temperature of the cycloolefin polymer is less than or equal to the crystallite melting temperature of the alpha-olefin polymer, and the polyolefin film has a shrinkage at 130 C. after 5 minutes, as measured according to ISO 11501, of less than or equal to 2%. These polyolefin films are excellently suited as dielectrics for capacitors and are distinguished by a low shrinkage at high temperatures. The cycloolefin polymer preferably forms a co-continuous phase in a matrix of the semi-crystalline alpha-olefin polymer, providing improved mechanical and electrical properties including a dielectric strength from 500 to 750 V/m.

Catalyst systems and methods for making and using the same. A method of polymerizing olefins to produce a polyolefin polymer with a multimodal composition distribution, includes contacting ethylene and a comonomer with a catalyst system. The catalyst system includes a first catalyst compound and a second catalyst compound that are co-supported to form a commonly supported catalyst system. The first catalyst compound includes a compound with the general formula (C.sub.5H.sub.aR.sup.1.sub.b)(C.sub.5H.sub.cR.sup.2.sub.d)HfX.sub.2. The second catalyst compound includes at least one of the following general formulas: In both catalyst systems, the R groups can be independently selected from any number of substituents, including, for example, H, a hydrocarbyl group, a substituted hydrocarbyl group, or a heteroatom group, among others.

A door assembly. The door assembly may include at least one door panel and a door frame having a plurality of frame members including a header and a pair of side jambs. The invention may also be considered a frame member. The frame member may include a core; and a two-piece top piece adjoining the core to form a structural member. The core and the top piece may be a composite of cellulosic material and at least one other material. The door assembly may further include at least one adjacent panel. Also disclosed are door jamb frame members and mullion frame members.

Fluorided silica-coated alumina activator-supports have a bulk density from 0.15 to 0.37 g/mL, a total pore volume from 0.85 to 2 mL/g, a BET surface area from 200 to 500 m.sup.2/g, an average pore diameter from 10 to 25 nm, and from 80 to 99% of pore volume in pores with diameters of greater than 6 nm. Methods of making the fluorided silica-coated alumina activator-supports and using the fluorided silica-coated aluminas in catalyst compositions and olefin polymerization processes also are described. Representative ethylene-based polymers produced using the compositions and processes have a melt index of 0.1 to 10 g/10 min and a density of 0.91 to 0.96 g/cm.sup.3, and contain from 70 to 270 ppm solid oxide and from 2 to 18 ppm fluorine.

Catalyst systems and methods for making and using the same. A method of methylating a catalyst composition while substantially normalizing the entiomeric distribution is provided. The method includes slurrying the organometallic compound in dimethoxyethane (DME), and adding a solution of RMgBr in DME, wherein R is a methyl group or a benzyl group, and wherein the RMgBr is greater than about 2.3 equivalents relative to the organometallic compound. After the addition of the RMgBr, the slurry is mixed for at least about four hours. An alkylated organometallic is isolated, wherein the methylated species has a meso/rac ratio that is between about 0.9 and about 1.2.

The present invention relates to a high-melt-strength polypropylene resin, and a preparation method therefor. A method for preparing the high-melt-strength polypropylene resin, according to the present invention, comprises the steps of: creating a polypropylene by polymerizing propylene monomers in the presence of a metallocene catalyst; and putting a diene compound and a comonomer into the created polypropylene and unreacted propylene monomers and reacting same, thereby forming a C40 or greater long-chain branch on the main chain of the polypropylene.

A method of polymerizing olefins is disclosed. The method comprises contacting ethylene and at least one co-monomer with a catalyst system to produce a polyolefin polymer that is multimodal. The catalyst system comprises a first catalyst that promotes polymerization of the ethylene into a low molecular weight (LMW) portion of the polyolefin polymer and a second catalyst that promotes polymerization of the ethylene into a high molecular weight (HMW) portion of the polyolefin polymer. The first catalyst and at least a portion of the second catalyst are co-supported to form a commonly-supported catalyst system and at least a portion of the second catalyst is added as a catalyst trim feed to the catalyst system.