Polymerization of ethylene to branched poly(ethylene)s using ansa-η5-monofluorenyl cyclohexanolato zirconium(IV) complex/methylaluminoxane
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ansa-η5-Monofluorenyl cyclohexanolato zirconium complex 3 was shown to be active for the polymerization of ethylene when activated with methylaluminoxane (MAO) at 5 bar. Up to a polymerization temperature of 40 °C, 3/MAO resulted in linear poly(ethylene)s with saturated chain ends. However, at polymerization temperatures of 60, 80, and 100 °C, a mixture of branched poly(ethylene)s, linear α-olefins and long chain alkanes was obtained. The poly(ethylene)s produced at 80 and 100 °C exhibited a bimodal molecular weight distribution indicative of multiple active species. Very high molecular weight (Mv > 5 × 105) linear poly(ethylene)s were obtained using 3/MAO at 25 °C.
Keywordsansa-Monofluorenyl complex Methyl aluminoxane Ethylene polymerization Branched poly(ethylene)s Bimodal MWD
AR thanks the Council for Scientific and Industrial Research, New Delhi, India for Junior and Senior Research Fellowships.
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