%0 Journal Article %A Romano, Dario %A Andablo-Reyes, Efren %A Ronca, Sara %A Rastogi, Sanjay %D 2015 %T Aluminoxane co-catalysts for the activation of a bis phenoxyimine titanium (IV) catalyst in the synthesis of disentangled ultra-high molecular weight polyethylene %U https://repository.lboro.ac.uk/articles/journal_contribution/Aluminoxane_co-catalysts_for_the_activation_of_a_bis_phenoxyimine_titanium_IV_catalyst_in_the_synthesis_of_disentangled_ultra-high_molecular_weight_polyethylene/9234143 %2 https://repository.lboro.ac.uk/ndownloader/files/16815638 %K UHMWPE %K Disentangled %K Polymerization %K Materials Engineering not elsewhere classified %X New activation systems for the bis[N-(3-tert-butylsalicylidene)pentafluoroanilinato] Ti (IV) dichloride catalyst (FI) for the synthesis of ultra-high molecular weight polyethylene (UHMWPE) with reduced entanglement density are explored. Together with the well-studied FI catalyst-methylaluminoxane (MAO) catalytic system, different aluminoxanes, namely polymethylaluminoxane-improved performance (PMAO), modified methylaluminoxane type 12 (MMAO12) and type 3A (MMAO3A) have been used. The catalyst activity increases with the addition of a co-catalyst modifier (2,6-di-tert-butyl-4-methylphenol, BHT). For an example when using MMAO3A as co-catalyst in combination with BHT the catalyst activity increases by tenfold. The synthesized UHMWPEs have been characterized via rheology, differential scanning calorimetry and uniaxial solid-state deformation to evaluate the influence that the different co-catalysts have on the catalyst activation and the entangled state of the polymer. Entanglement density increases when PMAO is used as a co-catalyst influencing the rheological response of the polymer melt and melting kinetics of nascent powder. Mechanical properties increase when MMAO12 is used in place of MMAO3A as co-catalyst. However, the earlier reported mechanical properties of UHMWPE synthesized using the FI/MAO are found to be better than those obtained using the co-catalysts investigated in this study. %I Loughborough University