Linear low density polyethylene from ethylene as an o nly monomer was prepared by the combination catalyst system of Et(Ind) 2ZrCl 2 an d {2 [2 Me 4 Br C 6H 3NC(Me)] 2C 5H 3N}FeCl 2 activated with methy laluminoxane (...Linear low density polyethylene from ethylene as an o nly monomer was prepared by the combination catalyst system of Et(Ind) 2ZrCl 2 an d {2 [2 Me 4 Br C 6H 3NC(Me)] 2C 5H 3N}FeCl 2 activated with methy laluminoxane (MAO).The two catalysts were well matched in a single reactor and i t was observed that the “comonomer effect" appeared in the in situ copolymeriz ation of ethylene.The comonomer effect was some strongly influenced by the molar ratio of Al to (Fe+Zr) and the polymerization temperatures.At 60℃ and n(Al )/n(Fe+Zr)=2000,the maximum activity of the catalytic system(8 5×10\+6g/mo l·h) was 4\^25 times higher than that of homopolymerization of ethylene(2\^0×1 0\+6g/mol·h),and the value of n(Fe)/n(Zr) was 0 5.At n(Al)/n(F e+Zr)=1000,the maximum activity diminished.When polymerization temperatures incr eased,the maximum activity of the in situ copolymerization decreased and the co rresponding ratio of Fe to Zr also decayed.The copolymers made from this catalyt ic system had the characteristics of low melting point(from 132 34℃ to 70 97 ℃),low density(from 0 9467?g/cm\+3 to 0\^9283?g/cm\+3) and narrow molecular weight distribution(from 2\^29 to 1\^86).However,it’s no obvious influence of th e comonomer effect on the physical properties of the copolymers.展开更多
制备了N,N-二(2,6-二异丙基苯基)苊二亚胺氯化镍,与A lE t2C l组成催化体系,催化4-乙烯基吡啶(4-VP)的聚合。研究表明,该催化体系可以有效地催化4-乙烯基吡啶聚合,并具有较高的活性,聚合条件如单体浓度、铝镍摩尔比、聚合温度和聚合时...制备了N,N-二(2,6-二异丙基苯基)苊二亚胺氯化镍,与A lE t2C l组成催化体系,催化4-乙烯基吡啶(4-VP)的聚合。研究表明,该催化体系可以有效地催化4-乙烯基吡啶聚合,并具有较高的活性,聚合条件如单体浓度、铝镍摩尔比、聚合温度和聚合时间等对4-乙烯基吡啶的聚合反应活性有较大的影响。最佳反应条件是单体浓度为0.6 m o l/L、n(A l)/n(N i)为800、温度为30℃,这时催化活性达到47.2 kg P(4-VP)/m o l N i.h。展开更多
Divalent β-diketiminate lanthanide complexes LYbR（THF）（L=｛（2,6-Me2C6H3）NC（Me）｝2CH;R=C9H7（1）,CH3C5H4（2）,OC6H2-But2-2,6-Me-4（32））were synthesized by reducing the mixed-ligand trivalen（t） β-diketimina...Divalent β-diketiminate lanthanide complexes LYbR（THF）（L=｛（2,6-Me2C6H3）NC（Me）｝2CH;R=C9H7（1）,CH3C5H4（2）,OC6H2-But2-2,6-Me-4（32））were synthesized by reducing the mixed-ligand trivalen（t） β-diketiminate ytterbium chlorides synthesized in situ with Na-K alloy.These divalent lanthanide complexes exhibit good catalytic activity for the ring opening polymerization of ε-caprolactone.展开更多
文摘Linear low density polyethylene from ethylene as an o nly monomer was prepared by the combination catalyst system of Et(Ind) 2ZrCl 2 an d {2 [2 Me 4 Br C 6H 3NC(Me)] 2C 5H 3N}FeCl 2 activated with methy laluminoxane (MAO).The two catalysts were well matched in a single reactor and i t was observed that the “comonomer effect" appeared in the in situ copolymeriz ation of ethylene.The comonomer effect was some strongly influenced by the molar ratio of Al to (Fe+Zr) and the polymerization temperatures.At 60℃ and n(Al )/n(Fe+Zr)=2000,the maximum activity of the catalytic system(8 5×10\+6g/mo l·h) was 4\^25 times higher than that of homopolymerization of ethylene(2\^0×1 0\+6g/mol·h),and the value of n(Fe)/n(Zr) was 0 5.At n(Al)/n(F e+Zr)=1000,the maximum activity diminished.When polymerization temperatures incr eased,the maximum activity of the in situ copolymerization decreased and the co rresponding ratio of Fe to Zr also decayed.The copolymers made from this catalyt ic system had the characteristics of low melting point(from 132 34℃ to 70 97 ℃),low density(from 0 9467?g/cm\+3 to 0\^9283?g/cm\+3) and narrow molecular weight distribution(from 2\^29 to 1\^86).However,it’s no obvious influence of th e comonomer effect on the physical properties of the copolymers.
文摘制备了N,N-二(2,6-二异丙基苯基)苊二亚胺氯化镍,与A lE t2C l组成催化体系,催化4-乙烯基吡啶(4-VP)的聚合。研究表明,该催化体系可以有效地催化4-乙烯基吡啶聚合,并具有较高的活性,聚合条件如单体浓度、铝镍摩尔比、聚合温度和聚合时间等对4-乙烯基吡啶的聚合反应活性有较大的影响。最佳反应条件是单体浓度为0.6 m o l/L、n(A l)/n(N i)为800、温度为30℃,这时催化活性达到47.2 kg P(4-VP)/m o l N i.h。
文摘Divalent β-diketiminate lanthanide complexes LYbR（THF）（L=｛（2,6-Me2C6H3）NC（Me）｝2CH;R=C9H7（1）,CH3C5H4（2）,OC6H2-But2-2,6-Me-4（32））were synthesized by reducing the mixed-ligand trivalen（t） β-diketiminate ytterbium chlorides synthesized in situ with Na-K alloy.These divalent lanthanide complexes exhibit good catalytic activity for the ring opening polymerization of ε-caprolactone.
