以卤代苯酚为原料,在咪唑和4-二甲氨基吡啶存在下,与三乙基氯硅烷反应,得到酚氧邻位为三乙基硅基取代的取代苯酚,随后与多聚甲醛反应,得到取代水杨醛,与伯胺通过醛胺缩合,得到苯氧亚胺配体,最后与金属络合,得到两种含三乙基硅基的苯氧...以卤代苯酚为原料,在咪唑和4-二甲氨基吡啶存在下,与三乙基氯硅烷反应,得到酚氧邻位为三乙基硅基取代的取代苯酚,随后与多聚甲醛反应,得到取代水杨醛,与伯胺通过醛胺缩合,得到苯氧亚胺配体,最后与金属络合,得到两种含三乙基硅基的苯氧亚胺锆催化剂,用于催化乙烯聚合制备超高分子量聚乙烯。在聚合温度为70℃,乙烯压力1.0 MPa,n(Al)/n(Zr)=7000条件下,以甲苯为溶剂,催化剂j的催化活性可达8.45 kg PE/(mmol·Zr·h),所得聚乙烯的黏均分子量介于100×104~800×104 g/mol,其熔点139℃,结晶度49.7%。展开更多
A series of Ti(Ⅳ) dichloride and dialkoxide com plexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been synthesized.The molecular structures of complexes 1 and 4...A series of Ti(Ⅳ) dichloride and dialkoxide com plexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been synthesized.The molecular structures of complexes 1 and 4 were established by single-crystal X-ray diffraction studies.The complexes adopt a distorted octahedral coordination structure around the titanium atom and two oxygen atoms are situated in trans position while two nitrogen atoms and two outgoing ligands(Cl or iPrO) are situated in cis position.Effect of activators(MMAO-12 and combinations Et_nAICl_(3-n)+Bu_(2)Mg) and outgoing ligand(Cl or iPrO) nature on the catalytic activity and properties of the resulting polymers was studied.The Ti complexes,despite the nature of the outgoing ligands(Cl or iPrO) in the presence of Al/Mg activators,was found to display a high ethylene polymerization activity in the range 1600-3830 kg_(polymer)·mol_(Ti)^(-1)·h^(-1)·atm^(-1) with a viscosity average molecular weight(M_v) value in the range 1.1×10~6-7.1×10~6 Dalton(Da).The resulting UHMWPE can be processed by a solventless method into high-strength and high-modulus oriented films.The rheological characteristics of a polymer melt have been studied.The absence of a cross-over point did not allow to compare the values of the molecular weight distribution of polymers obtained on fluorinated and non-fluorinated pre-catalysts,however,the estimation of the entanglement density is in good agreement with the mechanical characteristics of oriented film s.Upon activation with methylalumoxane,the activity of the com plexes decreased very significantly;however,a polymer with a molecular weight of about 12 million Da was obtained.In the process of ethylene/octene-1 copolymerization,fluorine-containing precatalysts showed a clear advantage over non-fluorinated analogues both in activity and in comonomer content.展开更多
The net charges on central metals of a serial non-metallocene early transition metal catalysts (FI catalyst) with similar steric hindrance were caculated with MM-QEq (molecular mechmism-charge equilibration) method an...The net charges on central metals of a serial non-metallocene early transition metal catalysts (FI catalyst) with similar steric hindrance were caculated with MM-QEq (molecular mechmism-charge equilibration) method and associated with ethylene polymerization activities of these FI catalyts. It was found that the activity increased with the net charge on metal if ignoring the influence of the steric hindrance. In other words, introduction of strong and/or more electron-withdrawing groups onto the ligand of FI catalyst would enhance the activity of the catalyst. This conculsion gave a direction to designing new FI catalyst with higher activity.展开更多
文摘以卤代苯酚为原料,在咪唑和4-二甲氨基吡啶存在下,与三乙基氯硅烷反应,得到酚氧邻位为三乙基硅基取代的取代苯酚,随后与多聚甲醛反应,得到取代水杨醛,与伯胺通过醛胺缩合,得到苯氧亚胺配体,最后与金属络合,得到两种含三乙基硅基的苯氧亚胺锆催化剂,用于催化乙烯聚合制备超高分子量聚乙烯。在聚合温度为70℃,乙烯压力1.0 MPa,n(Al)/n(Zr)=7000条件下,以甲苯为溶剂,催化剂j的催化活性可达8.45 kg PE/(mmol·Zr·h),所得聚乙烯的黏均分子量介于100×104~800×104 g/mol,其熔点139℃,结晶度49.7%。
基金supported by the Russian Science Foundation (No.22-23-00578)the financial support from the Ministry of Science and Higher Education of the Russian Federation using the equipment of Center for molecular composition studies of INEOS RAS (No.075-00697-22-00)the financial support of the Ministry of Science and Higher Education of the Russian Federation employing the equipment of Center for molecular composition studies of INEOS RAS。
文摘A series of Ti(Ⅳ) dichloride and dialkoxide com plexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been synthesized.The molecular structures of complexes 1 and 4 were established by single-crystal X-ray diffraction studies.The complexes adopt a distorted octahedral coordination structure around the titanium atom and two oxygen atoms are situated in trans position while two nitrogen atoms and two outgoing ligands(Cl or iPrO) are situated in cis position.Effect of activators(MMAO-12 and combinations Et_nAICl_(3-n)+Bu_(2)Mg) and outgoing ligand(Cl or iPrO) nature on the catalytic activity and properties of the resulting polymers was studied.The Ti complexes,despite the nature of the outgoing ligands(Cl or iPrO) in the presence of Al/Mg activators,was found to display a high ethylene polymerization activity in the range 1600-3830 kg_(polymer)·mol_(Ti)^(-1)·h^(-1)·atm^(-1) with a viscosity average molecular weight(M_v) value in the range 1.1×10~6-7.1×10~6 Dalton(Da).The resulting UHMWPE can be processed by a solventless method into high-strength and high-modulus oriented films.The rheological characteristics of a polymer melt have been studied.The absence of a cross-over point did not allow to compare the values of the molecular weight distribution of polymers obtained on fluorinated and non-fluorinated pre-catalysts,however,the estimation of the entanglement density is in good agreement with the mechanical characteristics of oriented film s.Upon activation with methylalumoxane,the activity of the com plexes decreased very significantly;however,a polymer with a molecular weight of about 12 million Da was obtained.In the process of ethylene/octene-1 copolymerization,fluorine-containing precatalysts showed a clear advantage over non-fluorinated analogues both in activity and in comonomer content.
基金the National Natural Science Foundation of China (Grant Nos. 20334030, 50703044 and 20734002)
文摘The net charges on central metals of a serial non-metallocene early transition metal catalysts (FI catalyst) with similar steric hindrance were caculated with MM-QEq (molecular mechmism-charge equilibration) method and associated with ethylene polymerization activities of these FI catalyts. It was found that the activity increased with the net charge on metal if ignoring the influence of the steric hindrance. In other words, introduction of strong and/or more electron-withdrawing groups onto the ligand of FI catalyst would enhance the activity of the catalyst. This conculsion gave a direction to designing new FI catalyst with higher activity.
