are amorphous materials not only with high transparency in the UV-vis region, but also with humidity-, thermal-resistance (high glass transition temperature, T g ). 1,2 These are mostly prepared by coordination copolymerization of ethylene with cyclic olefins, or ring-opening metathesis polymerization of multi-cyclic olefins and subsequent hydrogenation. The copolymerization approach seems promising in terms of modification of their compositions (cyclic olefin contents, etc.) and microstructures (including tacticity, etc.); COCs are commercialized (as TOPAS V R , APEL V R , etc.) as ultrapure (applicable to advanced pharma packaging, food contact films), crystal-clear (glass clear, amorphous), and high barrier (resistant to moisture, alcohols, acids) materials.2 Many reports are known for the ethylene copolymerization with norbornene (NBE) using ordinary metallocenes, 3 half-titanocenes,
Polymerizations of 1-decene (DC), 1-dodecene (DD), and 1-tetradecene (TD) by Cp*TiMe2(O-2,6-iPr2C6H3) (1)–[Ph3C][B(C6F5)4] (borate) catalyst have been explored in the presence of Al cocatalyst. The polymerizations of DC and DD, in n-hexane containing a mixture of AliBu3 and Al(n-C8H17)3, proceeded with high catalytic activities in a quasi-living manner, affording high molecular weight polymers (activity 4120–5860 kg-poly(DC)/mol-Ti·h, Mn for poly(DC) = 7.04–7.82 × 105, after 20 min at −30 °C). The PDI (Mw/Mn) values in the resultant polymers decreased upon increasing the ratio of Al(n-C8H17)3/AliBu3 with decreasing the activities at −30 °C. The PDI values also became low when these polymerizations were conducted at low temperatures (−40 or −50 °C); high molecular weight poly(DD) with low PDI (Mn = 5.26 × 105, Mw/Mn = 1.16) was obtained at −50 °C. The TD polymerization using 1–borate–AliBu3 catalyst (conducted in n-hexane at −30 °C) afforded ultrahigh molecular weight poly(TD) (Mn = 1.02 × 106, Mw/Mn = 1.38), and the PDI values also decreased with increasing the Al(n-C8H17)3/AliBu3 ratio.
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