Work

A Pore-Tailored Porous Organic Polymer-Supported Hafnocene Catalyst with High Activity to Make Ultra-High Molecular Weight Polyethylene with Narrow Molecular Weight Distribution under Industry Accessible Mild Conditions

Year: 2026

Type: article

Abstract: The industrial manufacturing of ultra-high molecular weight polyethylene (UHMWPE) via single-site catalysts e.g. metallocene catalysts is a very attractive research topic in the academic and/or industrial community, and the catalyst typically requires elaborate ligand structure design and complex carrier preparation to get high activity and controllable polymer properties under industry accessible mild conditions. Herein, we report a pore-tailored porous organic polymer (POP)-supported hafnocene catalyst with high activity for producing UHMWPE with narrow molecular weight distribution(polydispersity index <2.5), the polymerization temperature is 75 °C and the polymerization pressure of 1.0 MPa, these mild conditions showed greater potentials for a drop-in-industrialization. POP carriers with tunable pore structures were prepared via a direct knitting method. Upon supporting methylaluminoxane (MAO) and hafnocene complexes, the resulting catalysts exhibited uniform active-site dispersion and high ethylene polymerization activity. Notably, the catalyst based on a POP support with tailored pore architecture achieved an activity of 30,598 kgPE·(mol Hf)−1·h–1 and produced polyethylene with a viscosity-average molecular weight of 1.70 × 106 g/mol, which qualifies as UHMWPE, and the polydispersity index (PDI) is 2.4. The pore size, morphology, and mechanical strength of the support, together with the type, activation degree, and distribution of the active centers, were identified as key factors that jointly govern the catalytic performance and polymer molecular weight. This work demonstrates the potential of pore-engineered POPs as versatile carriers for metallocene-catalyzed synthesis of high-performance polyethylene.

Source: Polymer science & technology.

DOI: 10.1021/polymscitech.6c00092