Abstract: Polymerization processes for ethylene and at least one mono-1-olefin comonomer having from about three to eight carbon atoms per molecule in the presence of a twice-aged catalyst system comprising chromium supported on a silica-titania support and a trialkylboron compound is provided. Novel ethylene copolymers also are produced.

Abstract: A novel loop/slurry olefin polymerization process is provided which produces ultra high molecular weight ethylene homopolymers and ultra high molecular weight ethylene copolymers. Catalyst systems used are selected from the group consisting of inorganic oxide supported titanium-containing catalyst systems, inorganic oxide supported organo-zirconium catalyst systems and inorganic oxide supported organo-hafnium catalyst systems.

Abstract: A method of determining the proportion of short-chain branching in an olefin copolymer process stream is disclosed. The short-chain branching may also be determined as a function of molecular weight in a sample having a range of molecular weights. In the method, at least two olefin copolymer training samples are provided. The respective samples have different, known proportions of short-chain branching. The infrared (e.g. FT-IR) absorbance spectra of the training samples in a wavenumber range are obtained. Calibration information is determined from the training samples by chemometrically correlating the differences in the infrared absorbance spectra of the training samples to the differences in the degree of short-chain branching in the training samples. This step generates calibration information that allows the degree of short-chain branching in a sample to be determined once its infrared absorbance spectrum is obtained.

Abstract: This invention provides oxide matrix compositions that can be utilized in catalyst compositions that are useful for polymerizing at least one monomer to produce a polymer. The oxide matrix composition comprises residual mineral components and an oxide precursor. The catalyst composition comprises contacting an organometal compound, an organoaluminum compound, and an oxide matrix composition. Processes for producing the oxide matrix composition and the catalyst composition are also provided.

Abstract: The invention relates to blow molding of an article having an inwardly projecting hollow boss with a closed end. A portion of a molten parison conforms to the shape of a fixed pin projecting from the face of a mold part to thereby form the hollow boss. The invention includes an apparatus comprising a reciprocable sleeve slidably received within the mold part over the pin. It has been found that by blow molding the parison with the sleeve initially extended with its end substantially flush with the end of the pin, followed by retracting the sleeve to a retracted position after a predetermined delay time, a boss with a thicker end results. Consequently, the boss end has greater structural integrity, and thus minimizes or eliminates the possibility of penetration and/or cracking of the boss end when a screw is threadedly received in the hollow boss.