A novel poly(1\|butene) was synthesized with η 5 \|pentamethylcyclopentadienyl\|tribenzyloxytitanium(Cp\+*Ti(OBz)\-3) and modified methylaluminoxane(MAO). The influence of various conditions (e.g., catalyst compositi...A novel poly(1\|butene) was synthesized with η 5 \|pentamethylcyclopentadienyl\|tribenzyloxytitanium(Cp\+*Ti(OBz)\-3) and modified methylaluminoxane(MAO). The influence of various conditions (e.g., catalyst composition, temperature, Al/Ti, pressure of monomer, and catalyst concentration) on the catalytic activity, molecular weight of the products were investigated in detail. It was found that the catalyst exhibited highest activity of 91 3kgPB/molTi·h at \%T\%=30℃, and Al/Ti(mol/mol)=200. The catalytic activity and molecular weight were sensitive to the TMA content in MAO and external TIBA. Catalytiac activity and molecular weight were decreased with increasing the content of TMA in MAO.External addition of TIBA can deactivated the catalyst. Molecular weight of the products was increased with decreasing temperature and Ti concentration. The catalyst had the highest activity at a Ti concentration of 1 0×10 -3 mol/L. The molecular weight of poly(1\|butene) is high, over one million by GPC method. The results showed that with this catalyst system, a high molecular weight poly(1\|butene) can be synthesized.展开更多
Pentamethylcyclopentadienyl) titanium triallyioxide[Cp *Ti(OCH 2-CH[CDS1]CH 2) 3] was used as the catalyst precursor for the synthesis of polybutene 1, methylalumiunoxane(MAO) as cocatalyst. The effects of the ratio o...Pentamethylcyclopentadienyl) titanium triallyioxide[Cp *Ti(OCH 2-CH[CDS1]CH 2) 3] was used as the catalyst precursor for the synthesis of polybutene 1, methylalumiunoxane(MAO) as cocatalyst. The effects of the ratio of n (Al) to n (Ti), polymerization temperature, and concentration of Ti on catalytic activity, molecular weight and chain structure were investigated in detail. The ether soluble fraction of the polybutene 1 was characterized with 13 C NMR, DSC, WAXD, and GPC. The results indicate that the polymers thus obtained are atactic and regioirregular, the weight average molecular weight of these polymers lies in the range of 3 0×10 5 to 7 0×10 5. Increasing the polymerization temperature can result in a decrease in the polymer molecular weight. But the molecular weight varies slightly with the ratio of n (Al) to n (Ti). The catalytic activity tends to decrease with the increase in polymerization temperature. was used as the catalyst precursor for the synthesis of polybutene 1, methylalumiunoxane(MAO) as cocatalyst. The effects of the ratio of n (Al) to n (Ti), polymerization temperature, and concentration of Ti on catalytic activity, molecular weight and chain structure were investigated in detail. The ether soluble fraction of the polybutene 1 was characterized with 13 C NMR, DSC, WAXD, and GPC. The results indicate that the polymers thus obtained are atactic and regioirregular, the weight average molecular weight of these polymers lies in the range of 3 0×10 5 to 7 0×10 5. Increasing the polymerization temperature can result in a decrease in the polymer molecular weight. But the molecular weight varies slightly with the ratio of n (Al) to n (Ti). The catalytic activity tends to decrease with the increase in polymerization temperature.展开更多
文摘A novel poly(1\|butene) was synthesized with η 5 \|pentamethylcyclopentadienyl\|tribenzyloxytitanium(Cp\+*Ti(OBz)\-3) and modified methylaluminoxane(MAO). The influence of various conditions (e.g., catalyst composition, temperature, Al/Ti, pressure of monomer, and catalyst concentration) on the catalytic activity, molecular weight of the products were investigated in detail. It was found that the catalyst exhibited highest activity of 91 3kgPB/molTi·h at \%T\%=30℃, and Al/Ti(mol/mol)=200. The catalytic activity and molecular weight were sensitive to the TMA content in MAO and external TIBA. Catalytiac activity and molecular weight were decreased with increasing the content of TMA in MAO.External addition of TIBA can deactivated the catalyst. Molecular weight of the products was increased with decreasing temperature and Ti concentration. The catalyst had the highest activity at a Ti concentration of 1 0×10 -3 mol/L. The molecular weight of poly(1\|butene) is high, over one million by GPC method. The results showed that with this catalyst system, a high molecular weight poly(1\|butene) can be synthesized.
文摘Pentamethylcyclopentadienyl) titanium triallyioxide[Cp *Ti(OCH 2-CH[CDS1]CH 2) 3] was used as the catalyst precursor for the synthesis of polybutene 1, methylalumiunoxane(MAO) as cocatalyst. The effects of the ratio of n (Al) to n (Ti), polymerization temperature, and concentration of Ti on catalytic activity, molecular weight and chain structure were investigated in detail. The ether soluble fraction of the polybutene 1 was characterized with 13 C NMR, DSC, WAXD, and GPC. The results indicate that the polymers thus obtained are atactic and regioirregular, the weight average molecular weight of these polymers lies in the range of 3 0×10 5 to 7 0×10 5. Increasing the polymerization temperature can result in a decrease in the polymer molecular weight. But the molecular weight varies slightly with the ratio of n (Al) to n (Ti). The catalytic activity tends to decrease with the increase in polymerization temperature. was used as the catalyst precursor for the synthesis of polybutene 1, methylalumiunoxane(MAO) as cocatalyst. The effects of the ratio of n (Al) to n (Ti), polymerization temperature, and concentration of Ti on catalytic activity, molecular weight and chain structure were investigated in detail. The ether soluble fraction of the polybutene 1 was characterized with 13 C NMR, DSC, WAXD, and GPC. The results indicate that the polymers thus obtained are atactic and regioirregular, the weight average molecular weight of these polymers lies in the range of 3 0×10 5 to 7 0×10 5. Increasing the polymerization temperature can result in a decrease in the polymer molecular weight. But the molecular weight varies slightly with the ratio of n (Al) to n (Ti). The catalytic activity tends to decrease with the increase in polymerization temperature.
