Polymerization of olefins with a novel dinuclear ansa-zirconocene catalyst having a biphenyl bridge

✍ Scribed by Hoang The Ban; Toshiya Uozumi; Kazuo Soga

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 130 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19980930)36:13<2269::aid-pola13>3.0.co;2-8

✦ Synopsis

Both the rac-and meso-dinuclear ansa-zirconocene catalysts (-C 12 H 8 {[SiPh(Ind) 2 ]ZrCl 2 } 2 ) were prepared by a coupling reaction between 2 equiv of diindenylphenylchlorosilane (rac-and meso-isomers) and 1 equiv of p-dilithiobiphenyl in diethyl ether at Ϫ80°C, followed by a successive reaction with ZrCl 4 ⅐ 2THF in THF at Ϫ78°C. Polymerizations of ethene and propene were conducted in a 1 dm 3 highpressure glass reactor equipped with a mechanical stirrer at 60, 80, 100, 120, and 150°C using methylalumoxane (MAO) as cocatalyst and toluene or decahydronaphthalene as the solvent. Copolymerization of ethene and 1-octene was also checked in brief. For ethene polymerization, the meso-catalyst was found to be more active, which displayed an extremely high activity to give linear polyethene with a high molecular weight and a narrow molar mass distribution (MMD). The apparent activity increased monotonously with rising polymerization temperature from 60°C up to 150°C, indicating that the active species are stable even at a high temperature. On the other hand, both the rac-and meso-catalysts showed very poor activities for propene polymerization. However, copolymerization of ethene and 1-octene proceeded at a high speed.