Molecular Catalysis ( IF 3.9 ) Pub Date : 2019-12-17 , DOI: 10.1016/j.mcat.2019.110735 Jessica V. Lamb , Joseph C. Abell , Jack E. McLaren , Jean-Charles Buffet , Zoë R. Turner , Dermot O'Hare
Five new group 4 ansa-bridged permethylindenyl complexes with either a dimethylsilane bridge or a tetramethyldisilane bridge have been synthesised and fully characterised. These complexes were supported on a hydrocarbon insoluble polymethylaluminoxane (sMAO) and their slurry-phase ethylene polymerisation performance was investigated. The highest activity was achieved using (CpMe,I*)Zr(CH2SiMe3)2 (8042 kgPE molZr–1 h–1 bar–1 at 60 °C) but a decrease in activity was observed with an increase in the length of the bridge. DSC analysis of the polymers revealed the production of HDPE with minimal branching and defects, while SEM showed the production of polymer particles with commercially desirable uniform, ‘popcorn’, morphology. GPC analysis showed the production of polyethylenes with Mw < 570 kg mol–1 at 80 °C. In addition, (Cp,I*)Zr(CH2SiMe3)2 was immobilised on MAO modified layered double hydroxide (LDHMAO). The slurry-phase polymerisation activity of (Cp,I*)Zr(CH2SiMe3)2 on this support system was similar to the sMAO support; however, the polymer morphology was much less uniform.
中文翻译:
使用组4淤浆相聚合乙烯袢-bridged permethylindenyl络合物负载在聚甲基
五个新组4的柄-bridged permethylindenyl配合物或者是二甲基硅烷桥或四甲基乙硅烷桥已被合成并充分表征。这些配合物负载在不溶于烃的聚甲基铝氧烷(sMAO)上,并研究了它们的淤浆相乙烯聚合性能。最高的活性是通过使用(Cp Me,I *)Zr(CH 2 SiMe 3)2(8042 kg PE mol Zr –1 h –1 bar –1在60°C下),但是随着桥长度的增加,活性降低。DSC对聚合物的分析表明,生成的HDPE具有最小的分支和缺陷,而SEM显示的聚合物具有商业上所需的均匀“爆米花”形态。GPC分析表明,在80°C下,M w <570 kg mol –1的聚乙烯的生产。此外,将(Cp,I *)Zr(CH 2 SiMe 3)2固定在MAO改性的层状双氢氧化物(LDHMAO)上。淤浆相的聚合活性该支持系统上的(Cp,I *)Zr(CH 2 SiMe 3)2与sMAO支持类似;但是,聚合物的形态不均一。