Random Propene/4-Methyl-1-Pentene Copolymers Synthesized With C-2 Symmetric Highly Isospecific Metallocenes

Propene (P)/4-methyl-1-pentene (Y) copolymers in a wide range of composition were prepared with isospecific single center catalysts, rac-Et(IndH(4))(2)ZrCl2 (EBTHI), rac-Me2Si(2-Me-BenzInd)(2)ZrCl2 (MBI), and rac-CH2(3-(t)BuInd)(2)ZrCl2 (TBI). C-13 NMR analysis of copolymers and statistical elaboration of microstructural data at triad level were performed. Unprecedented and surprising results are here reported. Random P/Y copolymers were prepared with the most isospecific catalyst, TBI, that is known to prepare ethene/propene and ethene/4-methyl-1-pentene copolymers with long homosequences of both comonomers, whereas longer homosequences of both comonomers were observed in copolymers from the less enantioselective metallocenes EBTHI and MBI. These findings, which are against what is acknowledged in the field, can pave the way for the preparation on a large scale of random propene-based copolymers. (c) 2015 Wiley Periodicals, Inc.