Synthesis of Disentangled Ultra-High Molecular Weight Polyethylene using Vanadium(V)-Based Catalysts

Two known imido vanadium (V) trichloride complexes [Cl3V=N-C6H3-2,6-Me2] (1) and [Cl3V=N-C6H3-2,6-iPr2] (2), both of which have escaped testing as ethylene polymerization catalyst precursors, were synthesized and their capacity to polymerize ethylene in the presence of the co-catalyst MAO (methylaluminoxane) (Al:V ratio: 1000:1) at 10 oC is reported. The resulting polymers, from both pre-catalysts, have molecular weights exceeding 1-2 million g/mol as suggested by the insolubility at high temperature and rheological measurements. According to the rheological and DSC annealing characterizations the synthesized UHMWPE from both 1 and 2 show features of a high degree of disentanglement.