Abstract: A polypropylene composition comprises an isotactic polypropylene homopolymer resin that is suitable to form an injected molded article exhibiting less than about 60% haze, as determined by ASTM D1003, at a thickness of 0.05 inch without clarity-enhancing agents. The polypropylene composition has particular application to injection molded articles and may have a melt flow rate of from about 0.1 g/10 min to about 150 g/10 min as determined by ASTM D-1238, Procedure B. The resin may be prepared using a metallocene catalyst, and the composition may include clarity-enhancing agents for even greater clarity improvements.

Abstract: A guest host assembly comprising a host assembly formed of calixarene molecules and a guest component located within the host assembly. A crystallographic assembly of layers of the calixarene molecules and stacked along the crystallographic c axis of the assembly in a repeating configuration associated together predominantly by van der Waal forces. The guest component is transferable through the host assembly in a direction normal to the stacked layers. The calixarene molecules are configured in bilayers of adjacent layers along the c axis. The bilayers are shifted along the a or b axis so the assembly, relative to a corresponding assembly of the calixarene molecules without the inclusion of the guest component is shifted. The calixarene are calix(N)arenes in which N is an integer within the range of 4–8. The calixarene molecules are distally substituted with a substituent such as methyl, ethyl, propyl, butyl amyl or phenyl groups.

Abstract: The present invention is concerned with single layer articles produced by rotomoulding and consisting essentially of metallocene-produced syndiotactic polypropylene or isotactic random copolymer of propylene.

Abstract: A process for producing polypropylene having increased melt strength, the process comprising irradiating polypropylene which has been polymerised using a Ziegler-Natta catalyst with an electron beam having an energy of at least 5 MeV and a radiation dose of at least 10 kGray and mechanically processing the irradiated polypropylene to form long chain branches on the polypropylene molecules, whereby the polypropylene has a melt flow index (MFI) of at least 25 dg/min.

Abstract: A method for the storage of hydrogen within a subterranean solid carbonaceous formation such as a coal seam. At least one well extends from the surface of the earth into the formation and a pressure gradient extends from the formation to the well to desorb methane within the formation and flow the methane into the well. Subsequent to recovery of the methane from the formation, gaseous hydrogen is injected into the well and into the formation. The injection of hydrogen is carried out under a pressure sufficient to cause the injected hydrogen to become absorbed within the matrix of the carbonaceous formation. Subsequent to storage of the hydrogen, a pressure gradient is established from the formation to the surface to withdraw previously introduced hydrogen to the surface. At least one common well is used for recovery of methane from the formation and introduction of hydrogen into the formation.

Abstract: A guest-host assembly having a generally spheroidal host assembly formed of trimers of calixarene molecules in a hexagonal close-packed assembly and its preparation. The calixarene trimers are associated together predominantly by van der Waals forces to provide dilated channels having void volumes within the range of 100-200 ?3. A guest component, such as hydrogen, methane, or another hydrocarbon or halocarbon, is encapsulated within the dilated channels of the spheroidal host assembly and retained within the channels primarily by van der Waals forces. The guest-host assembly is stable at a temperature of 150° C. or higher. The temperature at which the onset of the release of the guest component occurs is within the range of 150-300° C.

Abstract: A polyethylene resin comprising from 35 to 49 wt. % of a first polyethylene fraction of high molecular weight and from 51 to 65 wt. % of a second polyethylene fraction of low molecular weight, the first polyethylene having a density of up to 0.930 g/cm3, and an HLMI of less than 0.6 g/10 min and the second polyethylene fraction comprising a high density polyethylene having a density of at least 0.969 g/cm3 and an MI2 of greater than 10 g/10 min, and the polyethylene resin, having a density of greater than 0.946 g/cm3, an HLMI of from 1 to 100 g/10 min, a dynamical viscosity, measured at 0.01 radians/second, greater than 200,000 Pa·s and a ratio of the dynamical viscosities measured at, respectively 0.01 and 1 radians/second greater than 8.

Abstract: Supported stereospecific catalysts and processes for the stereotactic propagation of a polymer chain derived from ethylenically unsaturated monomers such as the polymerization of propylene to produce syndiotactic polypropylene or isotactic polypropylene. The supported catalyst comprises a stereospecific metallocene catalyst component and a co-catalyst component comprising an alkylalumoxane. Both the metallocene catalyst component and the co-catalyst component are supported on a particulate polyorganosilsesquioxane support comprising spheroidal particles of a polyorganosilsesquioxane having an average. diameter with the range of 0.3–20 microns. The polyorganosilsesquioxane support is characterized by relatively low surface area, specifically a surface area less than 100 square meters per gram. The metallocene component can take the form of a single metallocene or two or more metallocenes which are co-supported on the polyorganosilsesquioxane support.

Abstract: The present invention relates to polypropylene resin compositions comprising a syndiotactic polypropylene incorporating at least one particulate material or chemical additive.

Abstract: Process for the production of an oriented polyolefin film using multi-component polymer compositions. One polymer component comprises an isotactic propylene homopolymer produced by the polymerization of propylene with a Ziegler-Natta catalyst. A secondary component is a Ziegler-Natta polymerized ethylene-propylene random copolymer or a metallocene-polymerized ethylene-propylene random copolymer produced by the polymerization of propylene and ethylene in the presence of a metallocene polymerization catalyst. The Ziegler-Natta polymerized copolymer is produced by the polymerization of ethylene and propylene in the presence of a Ziegler-Natta catalyst and contains no more than 0.5 wt. % ethylene and has a xylene solubles content of at least 2 wt. %. The primary and secondary polymer components are mixed together to provide a blend in which, when the secondary component is a Ziegler-Natta polypropylene, is present in an amount within the range of 5–25 wt.

Abstract: A process for cracking an olefin-rich hydrocarbon feedstock which is selective towards light olefins in the effluent, the process comprising contacting a hydrocarbon feedstock containing olefins having a first composition of at least one olefinic component with a crystalline silicate catalyst to produce an effluent having a second composition of at least one olefinic component, the feedstock and the effluent having substantially the same olefin content by weight therein as the feedstock. A process for the cracking of olefins in a hydrocarbon feedstock containing at least one diene and at least one olefin, the process comprising hydrogenating the at least one diene to form at least one olefin in the presence of a transition metal-based hydrogenation catalyst at an inlet temperature of from 40 to 200° C.

Abstract: Ethylene polymerization processes employing bis-imino pyridinyl transition metal components which exhibit C2, C2v or Cs symmetry. Catalyst components of the same or different symmetries may be employed to control polymerization characteristics and characteristics of the resulting polymer products such as polymer yield and polymer molecular weight. The transition metal catalyst component is characterized by the formula: wherein M is a Group 4–11 transition metal, n is an integer within the range of 1–3, Q is a halogen or a C1–C2 alkyl group, and PY is a pyridinyl group which is coordinated with M through the nitrogen atom of the pyridinyl group. Further, with respect to formula (I), A is a methyl group, a phenyl group, or a substituted phenyl group and B1 and B2 are the same or different aromatic groups depending on the symmetry of the catalyst component.

Abstract: A process and system for the vapor phase alkylation of an aromatic substrate in a multi-stage alkylation reaction zone having a plurality of series-connected catalyst beds spaced from one another to provide mixing zones between adjacent catalyst beds. A feedstock containing an aromatic substrate and a C2–C4 alkylating agent is supplied to an inlet side of the reaction zone. The reaction zone is operated at conditions in which the aromatic substrate is in the gas phase and causing vapor phase alkylation of the aromatic substrate as the aromatic substrate and the alkylating agent flow through the reaction zone and pass from one catalyst bed to the next. A quench fluid comprising one or both of the aromatic substrate and the alkylating agent is supplied into the interior of the mixing zone through a plurality of flow paths in which one portion of the flow paths is directed upwardly within the mixing zone and another portion downwardly within the mixing zone.

Abstract: Provided is a catalyst component for producing a polyolefin, which catalyst component comprises a metallocene catalyst having a structure according to formula (I): (THI)2R?MQp, wherein each THI is a tetrahydroindenyl derivative which may be substituted or unsubstituted, provided that at least one of the tetrahydroindenyl derivatives is substituted at the 2-position or the 4-position; R? is a structural bridge to impart stereorigidity between the two THI groups; M is a metal from Group IIIB, IVB, VB or VIB; Q is a hydrocarbyl group having from 1–20 carbon atoms, or a halogen; and p is the valence of M minus 2.

Abstract: A polyethylene resin comprising a blend of from 35 to 49 wt % of a first polyethylene fraction of high molecular weight and 51 to 65 wt % of a second polyethylene fraction of low molecular weight, the first polyethylene fraction comprising a linear low density polyethylene having a density of up to 0.928 g/cm3, and an HLMI of less than 0.6 g/10 min and the second polyethylene fraction comprising a high density polyethylene having a density of at least 0.969 g/cm3, and an MI2 of greater than 100 g/10 min, and the polyethylene resin, having a density of greater than 0.951 g/cm3 and an HLMI of from 1 to 100 g/10 min.

Abstract: A process for producing bimodal polyethylene resins in two reactors in series, the process comprising producing a first polyethylene resin fraction in a first slurry loop reactor in a diluent in the presence of a catalyst and producing a second polyethylene resin fraction in a second slurry loop reactor, serially connected to the first reactor, in the diluent in the presence of the catalyst, the first polyethylene resin fraction being passed from the first reactor to the second reactor together with the catalyst, one of the first and second reactors producing a resin fraction of higher molecular than the resin fraction produced by the other of the first and second reactors, characterised in that the first reactor is fed with a feed of ethylene and diluent having an ethylene content of at least 70 wt % based on the weight of the diluent and in that in the first reactor the slurry of polyethylene in the diluent has a solids content of at least 30 wt % based on the weight of the diluent.

Abstract: Olefin polymerization catalyst precursors are described herein. The precursors are generally characterized by the formula: wherein M is a transition metal selected from groups 8 to 10 of the Periodic Table; n is an integer of from 1 to 3; Q is a halogen or a C1 to C2 alkyl group; PY is a pyridinyl group, which is coordinated with M through the nitrogen atom of said pyridinyl group; R? is a C1 to C20 hydrocarbyl group; R? is a C1 to C20 hydrocarbyl group; A1 is a monoaromatic group, which is substituted or unsubstituted; and A2 includes multiple aromatic groups, which are substituted or unsubstituted.

Abstract: The present invention relates to the improvement of metal bond strength in polypropylene films surface treated at higher levels through the addition to the basic isotactic polypropylene (iPP) polymer of an amount of syndiotactic polypropylene (sPP) in an amount no more than about 10 percent by weight and preferably in an amount between about 0.5 percent and about 8 percent by weight. The invention encompasses both the resulting metallized polypropylene films with enhanced bond strength and the process for producing such films. The prescribed use provides improved bonding properties over a simple non-blended isotactic polypropylene homopolymer, while maintaining at acceptable levels the optical and physical characteristics of a film made from non-blended iPP homopolymer. At increasing percentages of sPP above the preferred levels, bond strength continues to increase, but a deterioration in other properties may be noted, particularly in the optical property haze.

Abstract: The invention comprises novel undoped and doped nanometer-scale CeO2 particles as well as a novel semi-batch reactor method for directly synthesizing the novel particles at room temperature. The powders exhibited a surface area of approximately 170 m2/g with a particle size of about 3–5 nm, and are formed of single crystal particles that are of uniform size and shape. The particles' surface area could be decreased down to 5 m2/g, which corresponds to a particle size of 100 nm, by thermal annealing at temperatures up to 1000° C. Control over the particle size, size distribution and state of agglomeration could be achieved through variation of the mixing conditions such as the feeding method, stirrer rate, amount of O2 gas that is bubbled through the reactor, the temperature the reaction is carried out at, as well as heating the final product at temperatures ranging from 150° to 1000° C.

Abstract: A process for the production of partially oriented polypropylene fibers from syndiotactic polypropylene. Syndiotactic polypropylene is heated to a molten state and extruded to form a fiber preform. The fiber preform is spun at a forward spinning speed within the range of about 700–3500 meters per minute to produce a partially oriented fiber. The partially oriented fiber is wound without further substantial orientation of the fiber at a draw ratio of less than 1.5. By operating at a forward spinning speed of about 700 meters per minute or more, the partially oriented fiber has a greater tenacity than would be observed for a fiber formed from a corresponding spun isotactic polypropylene. The fiber preform is spun at a forward spinning speed of at least 100 meters per minute to provide a tenacity on the order of about 2 grams per denier or more. The fiber preform may be spun at a forward spinning speed of at least 1500 meters per minute to provide a tenacity of about 3 grams per denier.