In-Reactor Polypropylene Functionalization?The Influence of Catalyst Structures and Reaction Conditions on the Catalytic Performance

To unravel the relationship between silylene-bridged metallocene catalyst structures and polymerization conditions their effect on performance in in-reactor functionalization of polypropylene, behaviors rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2/MMAO, rac-Me2Si(Ind)2ZrCl2, rac-Me2Si(2-Me-4-Ph-Ind)2HfCl2, rac-Me2Si(Ind)2HfCl2 propylene/aluminum alkyl-passivated 10-undecen-1-ol copolymerization were compared. Kinetic analysis revealed higher catalytic activities for zirconocenes compared to analogous hafnocenes. Both zirconocene hafnocene with substituted indenyl ligands afforded a molecular weight capability, improved stereo-selectivity, enhanced ability incorporate functionalized comonomers non-substituted congeners. An in-depth study polypropylene using best performing system, at temperatures ranging from 40 100 °C, linear inversely proportional correlation temperature comonomer reactivity (?Tp ? ? r1), copolymer ?Mn), melting ?Tm). While well under standard laboratory conditions, rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2/MMAO showed limited stereo-selectivity capabilities high-temperature (130–150 °C) solution process conditions. Although immobilization rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2 onto silica, allowing it be used industrially relevant slurry gas-phase led an active catalyst, failed any comonomer.