Exxonmobil Chemical Patents Inc.

William J Zafian

Henri Aime Lammens

Methods for producing polyethylene compositions having broader melt index ratio and narrower molecular weight distribution in high pressure multi-feed tubular reactors are provided. The methods are useful in multi-feed tubular reactors comprising three or more reaction zones. The first reaction zone or the first and second reaction zone having a peak temperature that is lower than standard peak temperatures for polymerization of ethylene monomer in a tubular reactor.

High pressure polyethylene tubular reactor processes for improved wire coating product

Processes and systems for preparing copolymers of ethylene and a polar comonomer include contacting an initial feed comprising ethylene and a polar comonomer with a first polymerization initiator in a continuous stirred tank reactor to form a first polymer, which may then be contacted with second polymerization initiator in a plug flow reactor to form a second polymer. The process yields a second polymer having a lower melt flow index (and higher molecular weight) with high polar comonomer content. The polar comonomer may be, for example, vinyl acetate to prepare a poly(ethylene-vinyl acetate) copolymer having a vinyl acetate content of up to about 33% while maintaining the melt flow rate less than about 10 g/10 minutes without the use of fillers.

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Houston, TX, United States of America

William J Zafian