Some highly active η~5-pentamethylcyclopentadienyltribenzyloxy titanium complexes [Cp Ti(OBz)_3] activated by modified methylaluminoxane (mMAO) were prepared and used as the catalyst for styrene syndiospecific polyme...Some highly active η~5-pentamethylcyclopentadienyltribenzyloxy titanium complexes [Cp Ti(OBz)_3] activated by modified methylaluminoxane (mMAO) were prepared and used as the catalyst for styrene syndiospecific polymerization and propene atactic polymerization. Styrene could be copolymerized with propene when the propene was prepolymerized for a period, to which styrene and tri-isobutylaluminum (TIBA) were then added. The titled block copolymer together with the related homopolymers was obtained. The copolymerization porducts can be divided into the homopolymers and the copolymer by successive solvent extraction with boiling butanone, heptane and tetrahydrofuran (THF), and each fraction was characterized by ~13C NMR, DSC and WAXD. It was found that aPS and aPP were soluble in boiling butanone and heptane respectively. The block copolymer (sPS-b-aPP) composed of syndiottactic polystyrene segment was soluble in boiling THF and the residue was chiefly sPS.展开更多
文摘Some highly active η~5-pentamethylcyclopentadienyltribenzyloxy titanium complexes [Cp Ti(OBz)_3] activated by modified methylaluminoxane (mMAO) were prepared and used as the catalyst for styrene syndiospecific polymerization and propene atactic polymerization. Styrene could be copolymerized with propene when the propene was prepolymerized for a period, to which styrene and tri-isobutylaluminum (TIBA) were then added. The titled block copolymer together with the related homopolymers was obtained. The copolymerization porducts can be divided into the homopolymers and the copolymer by successive solvent extraction with boiling butanone, heptane and tetrahydrofuran (THF), and each fraction was characterized by ~13C NMR, DSC and WAXD. It was found that aPS and aPP were soluble in boiling butanone and heptane respectively. The block copolymer (sPS-b-aPP) composed of syndiottactic polystyrene segment was soluble in boiling THF and the residue was chiefly sPS.
