Transition Metal Catalysts for Olefin Polymerization

Transition Metal Catalysts for Olefin Polymerization

Princeton Docket # 14-3038

Presently, only free radical copolymerizations of ethylene and polar industrial monomers (e.g, vinyl acetate or acrylic acid) at high temperatures and very high pressures have been commercialized. This existing technology, however, inherently lacks precise control over the resulting polymer microstructure and precludes access to highly linear (co)polymers. It is therefore advantageous to develop alternative synthetic methods in which material properties can be tuned at will.

Researchers in the Department of Chemistry at Princeton University have developed a new class of single component late transition metal catalysts for coordination polymerization.  A first generation of palladium catalysts has been demonstrated on a small scale to produce predominantly linear polyethylenes with molecular weights up to 240,000 and average turnover frequencies up to 2.1 x 10⁵ h^-1. Polymer properties such as molecular weight and branching density can be tuned by modification of the supporting ligand of the catalyst. Furthermore, these catalysts exhibit remarkable persistence at elevated temperatures compared to existing technologies. This catalyst class has also been shown competent for the synthesis of linear, random copolymers of ethylene and polar alkene monomers (e.g., acrylates, acrylic acid). Thus, these robust catalysts can produce hydroxyl- or carboxylate-functionalized linear polyolefins from simple industrial monomers.