FI Catalysts for Olefin Polymerization—A Comprehensive Treatment

Design of Efficient Molecular Catalysts for Synthesis of Cyclic Olefin Copolymers (COC) by Copolymerization of Ethylene and α-Olefins with Norbornene or Tetracyclododecene

“…For examples, activities (TCD content) by [Et(Ind)2]ZrCl2 [32], [Ph2C(Ind)(Cp)]ZrCl2 [33], [Ph2C(Cp)(Flu)]ZrCl2 [33], [Me2C(3-MeC5H3)(Flu)]ZrCl2 [3], [Me2C(3-t BuC5H3)(Flu)]ZrCl2 [3] were 25 kg-polymer/mol-Zr•h (35 mol %), 31 (85 mol % at 90 °C), 24 (68), 1.3 (40), 0.4 (44), and respectively. Design of molecular catalysts for synthesis of new polymers with specified functions is one of the most attractive targets in the field of catalysis, polymer chemistry, and organometallic chemistry [37][38][39][40][41][42][43][44][45][46][47][48]. In this minireview, reported examples of copolymerization of COs (NBE, TCD) with olefins (ethylene, propylene, 1-hexene, 1-octene, etc.…”

UHMWPE/HDPE in-reactor blends, prepared by in situ polymerization: Synthetic aspects and characterization

“…Thus, two sets of polyethylene blends, containing ~10 and 5 wt% of SBA-15 were synthesized. Due to the living nature of the FI catalyst [24][25][26][27], when changing the polymerization time, the effect of the different molar masses in the properties of the materials can also be evaluated. The results obtained for the UHMWPE/HDPE blends together with the ones for the neat polymers and the nanocomposites, prepared with each one of the two individual catalysts, are summarized in Table 1.…”

“…On the other hand, when fixing the Ti:Zr proportion at 50:50, the results seem to point out a decrease of the molar mass of the blends at increasing Al/M T ratios (compare FIM010,and FIM013 or FIM001 and FIM006). This trend may be related to the role of trimethylaluminum, TMA (one of the different species present in MAO) on deactivation pathways that contribute to a loss of the polymerization control and that will reduce the polymer chain growth [19,25]. Figure 3 shows the thermogravimetric curves under inert and oxidative environments for the blends prepared at the longest times.…”

Aluminoxane co-catalysts for the activation of a bis phenoxyimine titanium (IV) catalyst in the synthesis of disentangled ultra-high molecular weight polyethylene

“…Studies along this line have been conducted in our research group using a bis(phenoxyimine) Titanium (IV) single site catalyst activated by a methylaluminoxane (MAO) co-catalyst [6,7]. This combination is considered one of the most active in ethylene polymerization [8] and has the additional advantage of being 'quasi-living' [9] (i.e. the molecular weight will increase with increasing the polymerization time in certain conditions) and producing a polymer with narrow molecular weight distribution: for these reasons, it is a good candidate to perform systematic studies on the influence that reaction conditions have on polymer properties.…”