Chevron Phillips Chemical Company LP

Melvin Hildebrand

Youlu Yu

Paul J DesLauriers

Chung Ching Tso

Max P McDaniel

Qing R Yang

David C Rohlfing

Qing Yang

A composition comprising a polyethylene wherein the composition is enriched in polymer molecules having topological variations by an enrichment factor &#x3c9; 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.

Hyperbranched polymers and methods of making and using same

Polymer fractions such as polyethylene fractions can be produced that have a PDI less than about 2.3 and a Mgreater 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.

Ultra high molecular weight polyethylene fractions having narrow molecular weight distributions and methods of making and using the same

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Bartlesville, OK, United States of America

Melvin Hildebrand