Cascade polymerization preparation method for branched polyethylene in absence of inert medium, branched polyethylene, and use

Abstract

The present disclosure relates to the technical field of polyolefins, olefin products, and olefin cascade polymerization reactions, and in particular to a cascade polymerization preparation method for a branched polyethylene in the absence of an inert medium, a branched polyethylene, and a use. The cascade polymerization preparation method for a branched polyethylene in the absence of an inert medium provided by the present disclosure comprises the following steps: under the catalysis of an oligomerization-copolymerization cascade catalytic system, ethylene undergoing oligomerization to generate even-carbon-numbered olefins, and at the same time, ethylene and the even-carbon-numbered olefins undergoing copolymerization to prepare a branched polyethylene, wherein the even-carbon-numbered olefins comprise even-carbon-numbered olefins having four or more carbon atoms; and the oligomerization-copolymerization cascade catalytic system comprises an oligomerization catalyst and a copolymerization catalyst. The method of embodiments of the present disclosure does not require the use of an inert medium, and the concentration of a comonomer, namely, the even-carbon-numbered olefins, is high, helping to improve the insertion rate of the even-carbon-numbered olefins. In addition, during the preparation of the branched polyethylene, some oligomerization products can be produced simultaneously, thereby improving the operating efficiency of a device.

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