Effect of para‐Substituents in Ethylene Copolymerizations with 1‐Decene, 1‐Dodecene, and with 2‐Methyl‐1‐Pentene Using Phenoxide Modified Half‐Titanocenes‐MAO Catalyst Systems

Abstract

Abstract Effect of para‐substituents in the ethylene (E) copolymerization with 1‐decene (DC), 1‐dodecene (DD), and with 2‐methyl‐1‐pentene (2M1P) using a series of Cp*TiCl2(O‐2,6‐iPr2‐4‐R‐C6H2) [R=H (1), tBu (2), Ph (3), CHPh2 (4), CPh3 (5), SiMe3 (6), SiEt3 (7), and newly prepared 4‐tBuC6H4 (8) and 3,5‐Me2C6H3 (9)]‐MAO catalyst systems has been studied. The activities in these copolymerization reactions were affected by the para‐substituent, and the SiMe3 (6), SiEt3 (7) and 3,5‐Me2C6H3 (9) analogues showed the higher activities at 50 °C in the E copolymerization reactions with DC (1.06–1.44×106 kg‐polymer/mol‐Ti⋅h), DD (1.04–1.88×106 kg‐polymer/mol‐Ti⋅h) than the others, whereas no significant differences were observed in the comonomer incorporations. Complexes 6 and 7 also showed the higher activities at 50 °C in the E/2M1P copolymerization, and the 2M1P incorporation was affected by the para‐substituent and the polymerization temperature; complex 9 showed better 2M1P incorporation at 25 °C.

Keywords

• ethylene copolymerization
• half-titanocenes
• homogeneous catalysis
• ligand effects
• titanium catalysts