Synthesis And Performance Of Late-transition Metal Nickel And Palladium Catalysts

Late-transition metal catalysts for olefin polymerization is developed after metallocene catalysts, it is a novel and high activity catalyst for olefin polymerization. It is easy to synthesize and have low oxophilic nature. The nickel and palladium catalysts have extrude advantage in catalyse singleness ethylene to manufacture LLDPE and catalyse copolymerization of ethylene and polar monomer. Many national scientists have interest in researching and developing the catalyst.Two kinds of Ni(II) , Pd(II)a-diimine late-transition metal complexes catalysts have been synthesized and examined for ethylene polymerization in combination with methylaluminoxane as co-catalysts. The effect of reaction conditions and the structure of catalysts were investigated systemly. The results show that: the Ni(II), Pd(II)a-diimine catalysts are all high activity catalyst for ethylene polymerization and the activity of Ni catalyst is up to 7.84xl07gPE/molNi.h(35℃ , 4.08MPa, Al/Ni=200), the activity of Pd is lower thant Ni. The structure of catalyst, especial the ortho-group of aniline has important effect on catalysts and molecular weight. The activity and molecular weight is decreasing with the reaction temperature increasing. The ratio of co-catalyst and catalyst has effect on activity and molecular weight. The activity is increasing and molecular weight is decreasing with the increasing of Al/Ni. But when Al/Ni is greater than 1000, the activity in change very slowly. The activity and molecular weight is increasing with the increasing of reaction pressure.