Study On Synthesis And Properties Of Later Transition Metal Catalyst With Active Groups

With the rapid development of the global economy, polyolefin matters play a more and more significant role in polymer materials. During the catalyst which used in the production process of polyethylene, much attention paid in the late transition metal catalyst, which is a new class of catalysts in recent years. Such catalysts can obtained with different molecular forms by altering the structure of polyolefin products, so as to realize molecular design and assembly of the polymerization of olefins, thus become the main trend of polyethylene industry catalyst. For now, when such a catalyst for load test, We found that most of the late transition metal catalyst mainly through in introducing active groups to aniline benzene ring position, and such methods will restrictions the changes on the benzene ring of aniline, resulting in reduced its variability greatly. Therefore, we use another way, that the structure of the carbon skeleton acenaphthene were changed, introducing active groups are directly supported on the carrier. Thus carried on the benzene ring of aniline substituents can be arbitrarily changed, which can greatly alter its structure, so as to adjust its catalytic properties and activity.Transition in the study of this subject, we synthesized seven different late transition metal catalysts, and were characterized by means of NMR analysis, elemental analysis corresponding ligand structure, confirmed its structure. And by polymerization under different experimental conditions (e.g., aluminum-nickel ratio, the ethylene pressure, temperature, etc.) of ethylene, study of the ability of the seven catalysts. The results showed that:the catalytically active and the relative molecular mass of the α, α’-diimine nickel-based polymerization catalyst system will be changes in the spatial structure of the catalyst; When the polymerization temperature is constant, the Cat.5 showed a better performance. Wherein the optimum reaction temperature Cat.1-Cat.7 respectively to 30 ℃,30℃,30 ℃,50 ℃,70℃,50℃ and 70 ℃, and increase with the polymerization reaction temperature, relative molecular polymerization product quality degradation; with increasing Al/Ni molar ratio, catalyst activity increased, but when the Al/Ni molar ratio is greater than a certain value, it will decrease catalyst activity. On the whole, the seven catalysts have the best catalyst activity when the Al/Ni in the vicinity of 1000. In which the Cat.2 can reach 5.87 × 105g/(mol · cat · h) when the Al/Ni is 1000, and the Cat.5 relative other several catalysts, with more excellent performance.