Macromolecules, Vol.32, No.18, 5723-5727, 1999
Copolymerization of atactic polypropene macromonomer with propene by an isospecific metallocene catalyst
Atactic polypropene macromonomer (PPM) with a number-average polymerization degree of ca 20 was synthesized by bis(pentamethylcyclopentadienyl)zirconium dichloride-methylaluminoxane and its structure was analyzed by H-1 and C-13 NMR spectroscopies. Copolymerization of propene and PPM was conducted with isospecific rac-dimethylsilylenebis(2-methylbenz[e]indenyl)zirconium dichloride using methylaluminoxane as a cocatalyst. The detailed analyses of resulting copolymers by GPC, DSC, and C-13 NMR proved that PPM was copolymerized with propene to give poly(propene-co-PPM). PPM content in the copolymer was found to be controlled by the amount of PPM in feed.
Keywords:LIGAND SUBSTITUTION PATTERN;ETHYLENE POLYMERIZATION;METHYLALUMINOXANE CATALYST;OLEFIN POLYMERIZATION;BIS(PENTAMETHYLCYCLOPENTADIENYL)ZIRCONIUM;COMPLEXES;1-OCTENE;CENTERS;HAFNIUM