Recycling of methylaluminoxane (MAO) cocatalyst in ethylene polymerization with supported metallocene catalyst

“Bound but Not Gagged”Immobilizing Single-Site α-Olefin Polymerization Catalysts

“…The resultant tethered precatalysts were active in olefin polymerization when contacted with a toluene solution of MAO. In some reports, the MAO solution could then be recycled back into a subsequent batch polymerization . Trimethylsiloxyl functionalized metallocenes, including several ansa -metallocenes have also been reported to react with the surface silyl-ether and silanol moieties…”

Chromium catalysts based on PNP(NR2)2 ligands for selective ethylene oligomerization

“…[ 20 ] It is found that a higher Al/Cr ratio is favorable for the catalytic activity of precatalyst 1 and promotes C 8 selectivity at the expense of the C 6 fraction (compare Entry 2 with Entries 4 and 5 in Table 2), as the available cocatalyst in the catalytic system might be insufficient to promote chain transfer to aluminum in precatalyst 1 ‐based catalyst and excess cocatalyst is required for a complete activation. [ 13,21 ] Higher or lower catalyst loading will affect the formation of the catalytically active species and the concentration of ethylene, which will result in different catalytic activity and selectivity of the catalytic system. [ 13,22 ] Therefore, the highest catalytic activity and C 6 selectivity of precatalyst 1 system are obtained when the mass loading is 0.3 mmol/L (Table 2, entry 6); however, low catalyst mass loading may enhance the combined (C 6 + C 8 ) selectivity from 83% to 96% (compare Entry 4 with Entries 6 and 7 in Table 2).…”

Fabrication and Characterization of Cu Doped CeO₂ by Hydrothermal Process for Antimicrobial Activity

“…Small particles having a relatively large surface energy are unstable, so it is diffused into relatively large particles, increasing the size of the particles. [17] Therefore, it is considered that the crystal size increases as the reaction time increases.…”