Value-added olefin-based materials originating from FI catalysis: Production of vinyl- and Al-terminated PEs, end-functionalized PEs, and PE/polyethylene glycol hybrid materials

This contribution reports on the selective synthesis of vinyl- and Al-terminated polyethylenes (PEs) using FI catalysts with dried methylaluminoxane (DMAO) or DMAO/trimethylaluminum, and the conversion of the resultant vinyl-terminated PEs to end-functionalized PEs and PE/polyethylene glycol (PEG) hybrid materials. The materials that are derived from the vinyl-terminated PEs are new PE-based materials featuring the presence of polar functional groups or polar polymer segments. Zr-FI catalysts containing sterically less encumbered substituents (e.g., methyl, cyclobutyl, cyclopentyl) on the imine-Ns selectively formed vinyl-terminated PEs (Mw 1900–14,000, vinyl functionality > 90%) with high efficiency. Conversely, a Zr-FI catalyst containing a sterically encumbered substituent (i.e., 2-i-propylphenyl) at the same position exclusively provided Al-terminated PEs (Mw 12,000–716,000) with high activity. Therefore, the selection of the particular substituent on the imine-N resulted in the selective production of both vinyl- and Al-terminated PEs. Starting from the vinyl-terminated PEs that were produced using the FI catalysts, epoxy-, diol-, triol-, diamino-, and succinic anhydride-terminated PEs and PE/PEG AB2- and AB3-type hybrid materials were developed with unique material properties.