A Simple and Efficient Route to Disentangled Ultrahigh Molecular Weight Polyethylene via β-Diketonate Titanium Catalysts

Ultrahigh molecular weight polyethylene (UHMWPE) exhibits outstanding properties and widespread application requirements, yet its processing challenges remain a major concern. In this study, a series of β-diketonate titanium catalysts were developed for the one-reactor synthesis of bimodal polyethylene (polyethylene wax/UHMWPE). The content of the polyethylene wax component (2–60 wt %) could be regulated by varying polymerization conditions and catalyst structure. Optimal catalytic activity was achieved at low temperatures (0 °C), yielding bimodal polymers with less than 5 wt % polyethylene wax content, where the UHMWPE component was confirmed to be in a disentangled state. The resulting polymer exhibited ultradrawability, with draw ratios reaching up to 300, yielding tapes with superior mechanical properties. This is the first report of β-diketonate titanium catalysts for disentangled UHMWPE. The catalysts were readily synthesized in one step from inexpensive industrial precursors, demonstrating excellent potential for industrial application. This system supports both melt and solid-state processing, providing a practical pathway to overcome UHMWPE processing limitations.