The ethylene-propylene copolymers obtained from half-titanocene catalyst

( η5-pentamethy-lcyclopentadienyl) titanium triallyloxide (Cp*Ti(OCH2CH=CH2)3) combined with methylalumiloxane (MAO)

have been characterized by several methods including solvent extraction

FT-IR

GPC

X-ray

DSC

TG and DMA mesurements.The ethylene-propylene copolymers could be fractionated by successive solvent extraction.Most of them gave mainly two fractions of ether-soluble and hexane-soluble characteristics

some others contained partly hexane-insoluble fraction.These two ether-soluble and hexane-soluble fractions have a similar chemical composition and structure in FT-IR spectra.They show no melting point in DSC mesurements and a wide dispersion peak of non-crystalline phase in X-ray diffraction analysis

indicating that the copolymers are random ones.Copolymers containing more ethylene segments have shown some sharp peaks indicating they are crystal line.The glass transition temperature(Tg) of copolymers increased with the increasing of propylene molar ratio in feeding comonomer from DMA mesurement.Ethylene/propylene copolymers have shown high molecular weight and narrow molecular weight distribution in GPC measurements.