A comparative study ethylene/1-hexene copolymerization with t-BuNSiMe_2FluTiMe_2 catalyst via various activators

摘要

Due to the catalyst abilities and co-catalyst, we can control the amounts of alpha-olefin insertion, short chain branching distribution and the triad distribution of copolymers. The different microstructure of copolymer will affect the polymer properties such as melting and glass transition temperatures, melt viscosity, and mechanical and optical properties, all of which define the type and useful range of application of these materials. Marks et.al has investigated alpha-olefin comonomer insertion enchantment concentrate on catalyst and cocatalyst nuclearity using many kinds of catalyst. They found that in single site polymerization system, the sequence of polymer insertion strongly depended on the bimetallic complexes of catalyst and cocatalyst that were employed in the system. In this report, we reported the copolymerization behaviors between the [t-BuNSiMe_2Flu]TiMe_2 catalyst (denoted as catalyst 1 hereafter) with the different activators, such as MAO series, MMAO series, B(C_6F_5)_4 and Ph_3CB(C_6F_5)_4. The main objective of this present study was also to determine the influence of cocatalyst employed on the obtained polymer microstructure toward ethylene/1-hexene copolymerization.