Unusual Effect of Diethyl Zinc and Triisobutylaluminium in Ethylene/1‐Hexene Copolymerisation using an MgCl2‐Supported Ziegler‐Natta Catalyst
Unusual Effect of Diethyl Zinc and Triisobutylaluminium in Ethylene/1‐Hexene Copolymerisation using an MgCl2‐Supported Ziegler‐Natta Catalyst
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DOI：
10.1002/macp.200500424
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发表时间：
2006-01
影响因子：
2.5
通讯作者：
S. S. Perin-S.;J. Severn;C. Koning;J. C. Chadwick
中科院分区：
文献类型：
--
作者：
S. S. Perin-S.;J. Severn;C. Koning;J. C. Chadwick
在以MgCl 2 /TiCl 4 /邻苯二甲酸二异丁酯为Ziegler-Natta型催化剂的乙烯/1-己烯共聚反应中，分别以三异丁基铝和二乙基锌为助催化剂和链转移剂，可得到比三乙基铝与二乙基锌并用时高得多的共聚单体引入量。三异丁基铝很容易与二乙基锌反应，产生金属锌，最有可能是通过形成中间氢化物物质。相比之下，已经发现在该体系中使用2，6_二甲基吡啶作为外部供体对共聚单体的掺入和分布具有相对较小的影响，表明丙烯聚合中从倾向性等规向间规传播的变化并不伴随着乙烯/ 1-己烯共聚中共聚单体分布的重大改善。
The use of triisobutylaluminium and diethyl zinc as cocatalyst and chain transfer agent respectively in ethylene/1-hexene copolymerisation, carried out with a Ziegler-Natta catalyst of type MgCl 2 /TiCl 4 /diisobutyl phthalate, has been found to give significantly higher comonomer incorporation than was obtained when triethylaluminium was used in combination with diethyl zinc. Triisobutylaluminium reacts readily with diethyl zinc, yielding metallic zinc, most likely via the formation of intermediate hydride species. In contrast, the use of 2,6-dimethylpyridine as external donor in this system has been found to have relatively little effect on comonomer incorporation and distribution, indicating that a change from tendentially isospecific to syndiospecific propagation in propene polymerisation is not accompanied by a major improvement in comonomer distribution in ethylene/ 1-hexene copolymerisation.