Synthesis of hydroxy-functionalized ultrahigh molecular weight polyethylene using fluorenylamidotitanium complex

Copolymerizations of ethylene and 1-dodecene were conducted with a series of ansa-fluorenylamidodimethyltitanium complexes, [t-BuNSiMe2Flu]TiMe2 (1a), [t-BuNSiMe2(2,7-tBu2Flu)]TiMe2 (1b), and [(1-adamantyl)NSiMe2(2,7-tBu2Flu)]TiMe2 (1c) activated by modified methylaluminoxane. The activity increased by the introduction of the alkyl groups on the fluorenyl and amido ligands, and 1c produced the highest molecular weight copolymers. Complex 1c also promoted copolymerization of ethylene and iBu3Al protected 10-undecen-1-ol with high activity (~2000 kg·mol−1·h−1), affording hydroxy-functionalized ultrahigh molecular weight polyethylene. The hydroxy content of the copolymers obtained was controllable by changing comonomer feed ratio. The introduction of a small amount of hydroxy group can alter the surface properties of polyethylene.