A class of rare earth catalysts containing nitrogen-containing heterocyclic carbene ligands and a method for catalyzing olefin polymerization

Abstract

The invention provides a rare-earth catalyst of a nitrogen-containing heterocyclic carbene ligand and an olefin polymerization catalyzing method of the rare-earth catalyst. The rare-earth catalyst comprises a part A and a part B, wherein the part A is nitrogen-containing heterocyclic carbene coordinated rare-earth complex LMR2X, L is a cyclopentadienyl ligand selected from a cyclopentadienyl ligand, an indenyl ligand and a fluorenyl ligand, X is the nitrogen-containing heterocyclic carbene ligand selected from imidazolyl carbene, imidazolinyl carbene, triazolyl carbene and thiazolyl carbene, M is rare-earth metal selected from Sc, Y, Lu, Gd, Sm and Nd, and R is alkyl directly connected with the rare-earth metal; the part B is organoboron reagents. By using the rare-earth catalyst of the nitrogen-containing heterocyclic carbene ligand, the chain transfer reaction of propylene monomers can be effectively inhibited so as to prepare the homopolymer and copolymer, with higher molecular weight and narrower molecular distribution, of the propylene monomers.

Description

technical field [0001] The invention belongs to the technical field of advanced manufacturing of high-performance polymer materials, and relates to a rare earth catalyst of nitrogen-containing heterocyclic carbene ligands that can be used for olefin polymerization. Background technique [0002] The chain transfer reaction is a bottleneck that restricts the wide application of rare earth catalysts, such as propylene monomers containing one methyl group and isobutylene monomers containing two methyl groups. Due to the severe chain transfer reaction, it is difficult to use rare earth catalysts to prepare higher molecular weight polymers things. Therefore, designing and synthesizing rare earth catalysts that can effectively inhibit the chain transfer reaction of propylene and isobutene monomers has always been a challenging work in this field. Due to the high activity of rare earth catalysts, stable valence state, wide selection range of olefin monomers, and effective regulatio...

AI Technical Summary

Problems solved by technology

The rare earth catalysts reported so far have poor ability to inhibit the chain transfer reaction of monomers such as propylene and isobutylene during the polymerization process, resulting in low polymerization activity and difficulty in preparing high molecular weight polymers.

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