The Synthesis Of Imide Nickel Halide Complexes And The Preparation Of Branched Polyethylene By Catalytic Ethylene Polymerization

In this thesis,a series of unsymmetric 1-(2,4-{(4-MeOC6H4)2CH}2-6-MeC6H2N)-2-(ArN)C2C10H6 and its corresponding nickel chloride complexes and nickel bromide complexes are discussed,which were used as precatalyst to produce moderately branched,high molecular weight and narrow distribution polyethylene.All compounds synthesized in the experiment(the target aniline compound,a single-sided compound with acenaphthene quinone as the framework,Five bilateral ligands of steric aniline of different sizes were introduced and complexes)were adequately characterized,including NMR,FT-TR,elemental analysis,and X-ray crystal diffraction.At the same time,the effect of the polymerization conditions on the catalytic activity of nickel complexes and molecular weight,molecular weight distribution,and branching degree of polymerization products(PE)was systematically studied by the synthesis of nickel complexes as precatalysts and though changing the aromatic location and size of the groups in the heartland of amine replaced to achieve the purpose of regulating the center of the metal electronic effect and space steric,we got the diversification of the structure and properties of polyethylene.This thesis includes the following four chapters:Chapter 1:IntroductionChapter 2:Synthesis of a series of[1-(2,4-{(4-MeOC6H4)2CH}2-6-MeC6H2N)-2-(ArN)C2C10H6]NiX2 and the target aniline compounds,single ligands,ligands and complexes were fully characterized,which were supported by the characterization data of by 1H NMR,13C NMR,FT-IR and elemental analysis.The 2H NMR spectra of Nil-Ni5 show that the presence of nickel has a significant effect on the chemical displacement of hydrogen atoms in the complexes,and also indicate the effective coordination between nickel and ligands.In addition,the accurate crystal structure of the complexes Ni2 and Ni6 was obtained through X-ray diffraction test,both of which were distorted tetrahedral geometric shapes,and the N-aryl ring was almost perpendicular to the adjacent imine carrier,revealing its potential capacity of catalytic ethylene polymerizationChapter 3:[1-(2,4-{(4-MeOC6H4)2CH}2-6-MeC6H2N)-2-(ArN)C2C10H6]NiX2 as efficient precatalyst for ethylene polymerization produce polyethylene with moderately branched,high molecular weight and narrow molecular weight distribution.Through screening using type of cocatalysts,the molar ratio of Al/Ni,polymerization temperature and polymerization conditions,such as Nil as precatalyst reached the highest catalytic activity 8.61 x 106 g PE mol(Ni)-1 h-1 can be observed when the polymerization temperature at 30?,Me2AlCl as cocatalyst,the molar ratio of Al/Ni at 600.The molecular weight of polyethylene was 2.87×105 g mol-1,the melting point was 121.2?,the molecular weight distribution value was 3.44,and the branching degree was 43 branches/1000C.The investigation of polymerization time indicated that precatalyst Nil not only had a short reaction induction period,but also a long catalytic life.The Ni2-Ni10 complexes obtained by changing the aryl imine group and halogen atom,producing the polyethylene with different molecular weight and branching degree were obtained by catalytic ethylene polymerization.Meanwhile,the systematic change of the structure of the complexes also had a significant effect on the catalytic activityChapter 4:Conclusion and Prospect.