Preparation Of Novel Late Transition Metal α - Diimine Catalyst And Its Catalysis For Olefin Polymerization

Polyolefin occupies the important position in the world general synthetic resin, and the synthesis of catalyst is one of the core technology in the polyolefin industry. Late transition metal olefin polymerization catalysts are new-type catalysts, which have been attracted much attention in many polyethylene catalysts.Late transition metal catalysts possess high catalytic activity for olefin polymerization, with single active center and wonderful molecular tailoring properties which could realize molecular design and assembly.Previous researchers usually changed the substituent on the acenaphthene ligand and loaded the preparation of catalysts to silica with the substituent on the ligand, but they did not change the groups on the ligand backbone.A series of a-diimine late transition mental nickel (11) complexes containing different groups on ligand backbone、acenaphthene ligand and other supported a-diimine late transition mental catalysts had been synthesized to study the properties of the polyolefin under the conditions of temperature、the ratio of rAl/nNi in this paper.The ligand structure was confirmed by HNMR.The results indicated that:the special structure of the catalysts had an important influence on the catalytic activity and molecular weight; The best reaction temperature for Catl、Cat9 and Cat 10 were 30℃ and the activity were 3.71×105 g-mol-1·h-1,1.46×105 g-mol-1·h-1,2.74×105 g·mol-1·h-1, then for Cat2、Cat7were 10℃ and the activity were 4.46×105 g·mol-1·h-1、 5.38×105 g·mol-1·h-1.It was found that the highest activity for Cat3 was 6.20×105 g-mol-1·h-1 when the temperature reached 0℃.The activity for Cat5、Cat6、 Cat8 were 9.29×105g·mol-1·h-1、24×105g-mol-1·h-1,6.27×105g·mol-1·h-1 when the temperature was 70℃,but the activity of Cat4 was not good.The catalytic activity were increased and then reduced with Al/Ni ratio increasing.In general, when the Al/Ni ratio was about 1500, catalysts show the best activity.