Abstract: A composition comprising a polyethylene wherein the composition is enriched in polymer molecules having topological variations by an enrichment factor ? and wherein the composition displays a long chain branching frequency of greater than about 0.5 long chain branches per 1000 total carbon atoms. A composition comprising an isolated Ziegler-catalyzed polyethylene having a long chain branching frequency of greater than about 0.5 long chain branches per 1000 total carbon atoms at the high molecular weight end.

Abstract: An analytical method comprising performing a first fractionation of a polymer sample based on differences in crystallizability to provide a first set of sample fractions, performing a first analysis on the first set of sample fractions, performing a second fractionation of the first set of sample fractions to produce a second set of sample fractions, performing a second analysis on the second set of sample fractions, and synchronizing the first fractionation and second fractionation to provide about concurrent analysis of the polymer sample.

Abstract: The present invention provides a polymerization process which is conducted by contacting an olefin monomer and at least one olefin comonomer in the presence of hydrogen and a metallocene-based catalyst composition. Polymers produced from the polymerization process are also provided, and these polymers have a reverse comonomer distribution, low levels of long chain branches, and a ratio of Mw/Mn from about 3 to about 6.

Abstract: A composition comprising a polyethylene wherein the composition is enriched in polymer molecules having topological variations by an enrichment factor ? and wherein the composition displays a long chain branching frequency of greater than about 0.5 long chain branches per 1000 total carbon atoms. A composition comprising an isolated Ziegler-catalyzed polyethylene having a long chain branching frequency of greater than about 0.5 long chain branches per 1000 total carbon atoms at the high molecular weight end.

Abstract: The present invention provides a polymerization process which is conducted by contacting an olefin monomer and at least one olefin comonomer in the presence of hydrogen and a metallocene-based catalyst composition. Polymers produced from the polymerization process are also provided, and these polymers have a reverse comonomer distribution, low levels of long chain branches, and a ratio of Mw/Mn from about 3 to about 6.

Abstract: The present invention provides a polymerization process which is conducted by contacting an olefin monomer and at least one olefin comonomer in the presence of hydrogen and a metallocene-based catalyst composition. Polymers produced from the polymerization process are also provided, and these polymers have a reverse comonomer distribution, low levels of long chain branches, and a ratio of Mw/Mn from about 3 to about 6.

Abstract: The present invention provides a polymerization process which is conducted by contacting an olefin monomer and at least one olefin comonomer in the presence of hydrogen and a metallocene-based catalyst composition. Polymers produced from the polymerization process are also provided, and these polymers have a reverse comonomer distribution, low levels of long chain branches, and a ratio of Mw/Mn from about 3 to about 6.

Abstract: Polymer fractions such as polyethylene fractions can be produced that have a PDI less than about 2.3 and a Mw greater than about 1,000,000 g/mol, 3,000,000 g/mol, or 6,000,000 g/mol. Such polyethylene fractions are separated from a UHMWPE parent polymer by first dissolving the parent polymer in a relatively good solvent. The conditions employed for such dissolution are selected to reduce the degradation of the parent polymer. The resulting parent solution is transported into a fractionation column in which a support is disposed. The fractionation column is thereafter operated at conditions effective to form a precipitate on the support comprising the desired polyethylene fraction. The polyethylene fraction may then be recovered from the fractionation column by repeatedly displacing a solvent/non-solvent mixture into the column to dissolve the polyethylene fraction. The relative concentrations of the solvent and the non-solvent are based on a solvent gradient profile of the polyethylene parent polymer.

Abstract: Polymer fractions such as polyethylene fractions can be produced that have a PDI less than about 2.3 and a Mw greater than about 1,000,000 g/mol, 3,000,000 g/mol, or 6,000,000 g/mol. Such polyethylene fractions are separated from a UHMWPE parent polymer by first dissolving the parent polymer in a relatively good solvent. The conditions employed for such dissolution are selected to reduce the degradation of the parent polymer. The resulting parent solution is transported into a fractionation column in which a support is disposed. The fractionation column is thereafter operated at conditions effective to form a precipitate on the support comprising the desired polyethylene fraction. The polyethylene fraction may then be recovered from the fractionation column by repeatedly displacing a solvent/non-solvent mixture into the column to dissolve the polyethylene fraction. The relative concentrations of the solvent and the non-solvent are based on a solvent gradient profile of the polyethylene parent polymer.

Abstract: Oxidation of alkylaromatics having a benzylic hydrogen atom is catalyzed by a catalyst comprising a palladium salt, a metal persulfate, a third metal salt, and a tin salt in a carboxylic acid for a period of time sufficient to convert the alkylaromatics to their corresponding oxidized derivatives. The catalyst is prepared by preheating the palladium salt and the metal persulfate at a temperature sufficient to provide the desired catalytic activity followed by addition of the third metal salt and the tin salt.

Abstract: A one-step process for preparing 2,5-dimethylhexane-2,5-dihydroperoxide and its alkyl derivatives comprises: (1) adding sulfuric acid to a 60-70% hydrogen peroxide solution to form a first reaction mixture where the first mixture is controlled at a temperature in the range of from about -10.degree. C. to about 10.degree. C.; (2) adding 2,5-dimethyl-2,5-dihydroxy hexane to the mixture held at a temperature in the range of from about -10.degree. C. to about 10.degree. C. or lower to form a second reaction mixture and maintaining the second mixture at a temperature in the range of from about 20.degree. C. to about 50.degree. C. for about 5 minutes to about 5 hours to form a slurry containing the solid product of 2,5-dimethylhexane-2,5-dihydroperoxide, unreacted reactants and impurities; (3) lowering the temperature of the slurry to the range of from about -10.degree. C. to about 10.degree. C.

Abstract: Oxidation of alkylaromatics having a benzylic hydrogen atom is catalyzed by a catalyst comprising a palladium salt, a metal persulfate, a third metal salt, and a tin salt in a carboxylic acid for a period of time sufficient to convert the alkylaromatics to their corresponding oxidized derivatives. The catalyst is prepared by preheating the palladium salt and the metal persulfate at a temperature sufficient to provide the desired catalytic activity followed by additon of the third metal salt and the tin salt.