Comonomer-Induced Stereo-Selectivity Enhancement in a C-2-Symmetric Metallocene-Catalyzed Propylene Polymerization
Comonomer-Induced Stereo-Selectivity Enhancement in a C-2-Symmetric Metallocene-Catalyzed Propylene Polymerization
复制标题
C-2-对称茂金属催化丙烯聚合中共聚单体诱导的立体选择性增强
DOI：
10.1002/marc.201400736
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发表时间：
2015
影响因子：
4.6
通讯作者：
Dong Jin-Yong
中科院分区：
文献类型：
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作者：
Ma Lin;Dong Jin-Yong
丙烯在rac - Et(Ind)2ZrCl2/MAO的aC2 -对称茂金属催化剂下，在40℃下，在反式、反式、顺式- 1,5,9 -环十二癸烯（(E，E，Z) - CDT）的环三烯存在下进行聚合。共聚单体的掺入相当低（<0.10 mol%）。然而，这是第一次表明，共聚单体引起聚丙烯等规性的显著增加（> %在[毫米]）。推测（E，E，Z） - CDT与金属中心配合形成共聚单体-络合活性位点，负责整个聚合反应，活性降低，但丙烯对映选择性增加。
Propylene polymerization is carried out with aC2‐symmetric metallocene catalyst ofrac‐Et(Ind)2ZrCl2/MAO at 40 °C in the presence of a cyclo‐triene oftrans,trans,cis‐1,5,9‐cyclododecatriene ((E,E,Z)‐CDT). Comonomer incorporations are rather low (<0.10 mol%). However, it is shown for the first time that the comonomer causes a noticeable increase in polypropylene isotacticity (>7% in [mmmm]). (E,E,Z)‐CDT is speculated to coordinate to the metal center forming comonomer‐complexed active sites in charge of the entire polymerization reaction with decreased activity however increased propylene enantiomorphic selectivity.