Extremely active α-olefin polymerization and copolymerization with ethylene catalyzed by a dMAO-activated zirconium(iv) dichloro complex having an [OSSO]-type ligand. Issue 108 (20th October 2015)

• Record Type: Journal Article
• Authors: Toda, Tomoyuki; Nakata, Norio; Matsuo, Tsukasa; Ishii, Akihiko
• Is Part Of: RSC advances. Volume 5:Issue 108(2015)
• Page Start: 88826
• Page End: 88831
• Publication Date: 2015-10-20
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra20846g
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : We report here the polymerization of α-olefins and copolymerization of ethylene with 1-hexene catalyzed by a zirconium complex incorporating an [OSSO]-type ligand with dried methylaluminoxane (dMAO) as an activator. Abstract : The ability of a zirconium(iv ) dichloro complex (6b ) incorporating an [OSSO]-type ligand5 with dMAO as an activator for the polymerization of 1-hexene and 4-methyl-1-pentene (4-MP) is described. In the polymerization of 1-hexene, the combination of the6b /dMAO catalyst system efficiently provided poly(1-hexene)s with completely isotactic [ mmmm ] pentad more than 95% and relatively large molecular weight ( M w = 40 000–150 000 g mol −1 ). The corresponding activity was recorded with quite high values up to 18 100 g mmol(6b ) −1 h −1, which increased significantly compared with those of the related non-Cp complexes. The polymerization of 4-MP using the6b /dMAO system at different temperatures also gave perfect isotactic poly(4-MP)s ([ mmmm ] > 95%) with moderate molecular weights ( M w = 7000–21 300 g mol −1 ), relatively narrow polydispersities ( M w / M n = 1.5–1.7), and activities of 1220–1690 g mmol(6b ) −1 h −1 . This catalyst system was also found to promote ethylene copolymerization with different amounts of 1-hexene at 25 °C under atmospheric pressure producing random ethylene/1-hexene copolymers ( M w = 10 100–17 300 g mol −1, M w / M n = 1.8–1.9, 1-hexene contents = 37.3–66.7 mol%) with fairly high activity up to 2700 g mmol(6b ) −1 h −1 .