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
研究了一系列不同烷基铝处理的TiClx/MgCl2/THF体系Ziegler-Natta催化剂,并采用XPS、EPR对其化学结构进行表征,初步探讨了烷基铝变化对催化剂化学结构的影响,特别是对Ti价态的影响。研究结果表明,由于烷基铝的作用,催化剂中活性组分Ti...研究了一系列不同烷基铝处理的TiClx/MgCl2/THF体系Ziegler-Natta催化剂,并采用XPS、EPR对其化学结构进行表征,初步探讨了烷基铝变化对催化剂化学结构的影响,特别是对Ti价态的影响。研究结果表明,由于烷基铝的作用,催化剂中活性组分Ti的结构发生了明显的改变,而其中烷基铝预还原过程对催化剂的结构影响较大。借助催化剂的这些结构上的变化引起其催化性能的显著提高,对比评价结果表明,小试催化剂的乙烯均聚活性从预还原前的4890 gPE/gcat提高到9300 g PE/gcat,工业生产催化剂从8400 g PE/gcat提高到11000 g PE/gcat。展开更多
综述了烷基铝对α-二亚胺镍催化体系在聚合反应中所产生的影响。甲基铝氧烷(MAO)以其较高的活化能力广泛运用于α-二亚胺镍等催化体系中。三甲基铝(TMA)、三异丁基铝(TiBA)等无氯烷基铝也都有一定的活化能力,但远不如MAO。二乙基氯化铝(...综述了烷基铝对α-二亚胺镍催化体系在聚合反应中所产生的影响。甲基铝氧烷(MAO)以其较高的活化能力广泛运用于α-二亚胺镍等催化体系中。三甲基铝(TMA)、三异丁基铝(TiBA)等无氯烷基铝也都有一定的活化能力,但远不如MAO。二乙基氯化铝(DEAC)、倍半乙基氯化铝(EASC)等含氯烷基铝有较强的活化能力,甚至比MAO的活化作用强得多,其中EASC和α-二亚胺镍配合可以使乙烯的聚合速率高达3966 kg PE/(mol Ni.h)。展开更多
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).
文摘研究了一系列不同烷基铝处理的TiClx/MgCl2/THF体系Ziegler-Natta催化剂,并采用XPS、EPR对其化学结构进行表征,初步探讨了烷基铝变化对催化剂化学结构的影响,特别是对Ti价态的影响。研究结果表明,由于烷基铝的作用,催化剂中活性组分Ti的结构发生了明显的改变,而其中烷基铝预还原过程对催化剂的结构影响较大。借助催化剂的这些结构上的变化引起其催化性能的显著提高,对比评价结果表明,小试催化剂的乙烯均聚活性从预还原前的4890 gPE/gcat提高到9300 g PE/gcat,工业生产催化剂从8400 g PE/gcat提高到11000 g PE/gcat。
文摘综述了烷基铝对α-二亚胺镍催化体系在聚合反应中所产生的影响。甲基铝氧烷(MAO)以其较高的活化能力广泛运用于α-二亚胺镍等催化体系中。三甲基铝(TMA)、三异丁基铝(TiBA)等无氯烷基铝也都有一定的活化能力,但远不如MAO。二乙基氯化铝(DEAC)、倍半乙基氯化铝(EASC)等含氯烷基铝有较强的活化能力,甚至比MAO的活化作用强得多,其中EASC和α-二亚胺镍配合可以使乙烯的聚合速率高达3966 kg PE/(mol Ni.h)。
文摘研究了用 Ni(acac)_2(2,4-戊二酮镍)或 Ni(dPP)_2(1,3-二苯基-1,3-丙二酮镍)/烷基铝均(?)催化体系进行的丙烯齐聚反应。用一系列 Et_2AIY 型的烷基铝(Y=((?)-C_6H_(12))_2N—、C_2H_5O—、n-C_4H_9O—、n-C_(?)H_(11)CO_2—、C_6H_5CO_2—等)作助催化剂时,发现催化剂活性与 Y 的电负性有关,而且只有当 HY 的酸性与β-二酮配体的酸性相适应时,催化剂才有离活性。
