Cp_2ZrCl_2/BF_3/SiO_2-MAO催化体系用于乙烯聚合的研究

Cp_2ZrCl_2/ BF_3 / SiO_2-MAO Catalytic System for Ethylene Polymerization

报道了Ｃｐ２ＺｒＣｌ２／ＢＦ３／ＳｉＯ２－ＭＡＯ催化体系的制备．发现在２５ｍＬ甲苯中加入Ｃｐ２ＺｒＣｌ２的量从６８．７ｍｍｏｌ增加到２７４．６ｍｍｏｌ，Ｚｒ在ＢＦ３／ＳｉＯ２上的负载量也随之从每克ＳｉＯ２中含有２０．４ｍｍｏｌ增加到４２．８ｍｍｏｌ．用该催化体系催化乙烯聚合结果表明，在相同Ａｌ／Ｚｒ比条件下，Ｃｐ２ＺｒＣｌ２／ＢＦ３／ＳｉＯ２－ＭＡＯⅡ活性最高．同时提出了制备反应的机理．

A model catalytic system Cp+2ZrCl_2/BF_3/SiO_2-MAO was prepared. It is foundthat with increasing added-Cp_2ZrCI_2 quanhty tyom 68.7 mmol to 274.6 mmol in 2.5 mltoluene, supported-Cp_2ZrCI_2 quantity on BF_3/ SiO_2 increases from 20.4 mmol to 42.8 mmolin per gram SiO_2 accordingly. The results of ethylene polylnerization using Cp_2ZrCl_2/BF_3/SiO_2-MAO catalytic systcm show that the activity of Cp_2ZrOl_2/BF_3/SiO_2 -MAO II ishighest at the same Al/Zr ratio.A preparation mechanism is suggested.