LIU Wei, SUN Chunyan, CHEN WEI, JING Zhenhua. THE STUDY OF SYNDIOSPECIFIC POLYMERIZATION OF PROPYLENE WITH SUPPORTED METALLOCENE CATALYST[J]. Acta Polymerica Sinica, 2002,(3):389-393.
LIU Wei, SUN Chunyan, CHEN WEI, JING Zhenhua. THE STUDY OF SYNDIOSPECIFIC POLYMERIZATION OF PROPYLENE WITH SUPPORTED METALLOCENE CATALYST[J]. Acta Polymerica Sinica, 2002,(3):389-393.DOI:
The syndiotactic polypropylene (sPP) with high bulk density and sphere-like was prepared in bulk process by syndiospecific metallocene catalyst
which was synthesized and supported on silica by ourself. To avoid the active center of the metallocene catalyst leaching from silica surface that would foul reactor in polymerization
the blend of methylaluminoxane (MAO) and metallocene catalyst was deposited on silica treated by MAO first
then washing three times at least by hexane.The polymerization was carried out in 5 L reactor.The results verified that the high polymerization activity and syndiospecification of the metallocene catalyst were preserved after being supported. The polymerization activity and the pentad concentration of sPP are more than 1066 g sPP/molZr·h and 75%
respectively. The morphology and distribution of sPP particles were modified remarkably.Through studying the polymerization process
the effects of the polymerization temperature and the catalyst concentration on the polymerization results were inspected including polymerization activity
polymer morphology and the bulk density of polymer. When polymerization activity is in the range of 3~4×106 g sPP/molZr·h
the sphere-like sPP with weight average molecular weight (Mw) between 15~45×104 and the bulk density between 0.35~0.45 g/cm3 was obtained.