Fluorinated bis(phenoxy-imine)titanium complexes with methylaluminoxane for the synthesis of ultra high molecular weight polyethylene

Effect of Activator and Outgoing Ligand Nature on the Catalytic Behavior of Bis(phenoxy-imine) Ti(IV) Complexes in the Polymerization of Ethylene and Its Copolymerization with Higher Olefins

“…It was found that with an increase in this ratio from 1:500 to 1:1000, the productivity slightly decreases, and the molecular weight of the polymer increases from 4.1 to 4.6 × 10 6 (experiments 13–14). This observation is consistent with the data [ 38 ], the authors of which believe that an increase in Al/Ti ratio leads to not only an increase in the number of active centers but also increases in the polarity of the medium, which leads to better ion separation and stabilization of the ion-pair. We also do not rule out that an increase in the Al/Ti ratio promotes the reduction of Ti(IV) to Ti(III).…”

Synthesis of Ultrahigh-Molecular-Weight Ethylene-1-Hexene Copolymers with High Hexene Content via Living Polymerization with Fluorinated Bis(phenoxy-imine) Titanium(IV)

“…[ 12,13 ] One of the challenges facing the living polymerization of olefi ns is its diffi culty in obtaining UHMW ethylene-α -olefi n copolymers having high α -olefi n contents. [ 4,14,15 ] Weiser et al [ 16,17 ] used a bis(phenoxy-imine) Ti catalyst to prepare EP copolymers of 2.2 × 10 6 g mol −1 with a propylene fraction in the copolymer of F 2 = 20 mol% and a polydispersity of the MWD of PDI = 1.9, and diblock copolymers of 2 × 10 6 g mol −1 with F 2 = 8 mol% and PDI = 1.6. However, literature examination revealed that preparation of UHMW ethylene-based copolymers with higher α-olefi ns, such as 1-hexene and 1-octene, has not been achieved.…”

“…With extremely extended chain length the polymer could exhibit distinctly novel and excellent properties . One of the challenges facing the living polymerization of olefins is its difficulty in obtaining UHMW ethylene‐ α ‐olefin copolymers having high α ‐olefin contents . Weiser et al used a bis(phenoxy–imine) Ti catalyst to prepare EP copolymers of 2.2 × 10 6 g mol −1 with a propylene fraction in the copolymer of F 2 = 20 mol% and a polydispersity of the MWD of PDI = 1.9, and diblock copolymers of 2 × 10 6 g mol −1 with F 2 = 8 mol% and PDI = 1.6.…”