A diphenoxybis(β diketonato)titanium complex, (dbm) 2Ti(OPh) 2, was synthesized and the corresponding MgCl 2\|supported catalyst was prepared by impregnation method. The polymerization activity was drastically improv...A diphenoxybis(β diketonato)titanium complex, (dbm) 2Ti(OPh) 2, was synthesized and the corresponding MgCl 2\|supported catalyst was prepared by impregnation method. The polymerization activity was drastically improved by using MgCl 2\|supported (dbm) 2Ti(OPh) 2 activated by aluminoxane (MAO) for ethylene polymerization (1.5×10 5 g/molTi with the heterogeneous catalyst and 1.3×10\+3 g/molTi with the homogeneous one). When the molar ratio of Al to Ti increased from 50 to 1000, the crystallinity and molecular weight of polyethylene were decreased rapidly. Also, the molecular weight of polyethylene was decreased from 5.1×10 5 to 2.8×10\+5 by increasing the molar content of titanium of the supported catalyst from 0.5×10 -5 to 3.42 ×10 -5 . After 60 min of the reaction, the molecular weight was at 5.0×10 5 or so. It is revealed that the MgCl 2\|supported β diketonato titanium complex is influenced by the polymerization conditions markedly.展开更多
Spherical MgCl 2 supported metallocene catalyst was prepared by supporting MAO on carrier which was prepared from MgCl 2 ·n EtOH.Ethylene polymerization was carried out by addition of MAO/MgCl 2,different metallo...Spherical MgCl 2 supported metallocene catalyst was prepared by supporting MAO on carrier which was prepared from MgCl 2 ·n EtOH.Ethylene polymerization was carried out by addition of MAO/MgCl 2,different metallocenes and alkylaluminum,in the absence of soluble MAO.It shows high activity for ethylene polymerization at lower Al/Zr(Al/Zr=45).The effect of concentration of Al( i Bu) 3 on polymerization activities and activation of Et(Ind) 2ZrCl 2 were studied.Kinetic behavior of ethylene polymerization on spherical MgCl 2 supported metallocene catalyst was investigated,which indicated the polymers obtained by reaction could affect the diffusion of ethylene in hexane under the experiment condidtion.Different aluminium alkyls have great impact on the whole polymerization behavior,and the relative reactivity decreases in the following order:Al( i Bu) 3>AlEt 3>AlMe 3>AlEt 2Cl,in which Al( i Bu) 3 shows the highest catalytic activity (5 78×10 7 g PE/mol\|Zr·h).展开更多
文摘A diphenoxybis(β diketonato)titanium complex, (dbm) 2Ti(OPh) 2, was synthesized and the corresponding MgCl 2\|supported catalyst was prepared by impregnation method. The polymerization activity was drastically improved by using MgCl 2\|supported (dbm) 2Ti(OPh) 2 activated by aluminoxane (MAO) for ethylene polymerization (1.5×10 5 g/molTi with the heterogeneous catalyst and 1.3×10\+3 g/molTi with the homogeneous one). When the molar ratio of Al to Ti increased from 50 to 1000, the crystallinity and molecular weight of polyethylene were decreased rapidly. Also, the molecular weight of polyethylene was decreased from 5.1×10 5 to 2.8×10\+5 by increasing the molar content of titanium of the supported catalyst from 0.5×10 -5 to 3.42 ×10 -5 . After 60 min of the reaction, the molecular weight was at 5.0×10 5 or so. It is revealed that the MgCl 2\|supported β diketonato titanium complex is influenced by the polymerization conditions markedly.
文摘Spherical MgCl 2 supported metallocene catalyst was prepared by supporting MAO on carrier which was prepared from MgCl 2 ·n EtOH.Ethylene polymerization was carried out by addition of MAO/MgCl 2,different metallocenes and alkylaluminum,in the absence of soluble MAO.It shows high activity for ethylene polymerization at lower Al/Zr(Al/Zr=45).The effect of concentration of Al( i Bu) 3 on polymerization activities and activation of Et(Ind) 2ZrCl 2 were studied.Kinetic behavior of ethylene polymerization on spherical MgCl 2 supported metallocene catalyst was investigated,which indicated the polymers obtained by reaction could affect the diffusion of ethylene in hexane under the experiment condidtion.Different aluminium alkyls have great impact on the whole polymerization behavior,and the relative reactivity decreases in the following order:Al( i Bu) 3>AlEt 3>AlMe 3>AlEt 2Cl,in which Al( i Bu) 3 shows the highest catalytic activity (5 78×10 7 g PE/mol\|Zr·h).
