Microstructure distribution of polypropylenes obtained in the presence of traditional phthalate/silane and novel diether donors: A tool for understanding the role of electron donors in MgCl2-supported Ziegler-Natta catalysts
Microstructure distribution of polypropylenes obtained in the presence of traditional phthalate/silane and novel diether donors: A tool for understanding the role of electron donors in MgCl2-supported Ziegler-Natta catalysts
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DOI：
10.1021/ma960070j
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发表时间：
1996-08-26
期刊：
影响因子：
5.5
通讯作者：
Tritto, I
中科院分区：
文献类型：
--
作者：
Morini, G;Albizzati, E;Tritto, I
三种二醚，2,2-二异丁基-1,3-二甲氧基丙烷、2,2-二环戊基-1,3-二甲氧基丙烷和2-乙基-2-丁基-1,3-二甲氧基丙烷，其2位烷基取代基的体积不同，已被用作丙烯聚合的MgCl2-TiCl4-二醚/AlR(3)催化剂中的内给体。通过将升温洗脱分级 (TREF) 分析与第一个单体单元插入的立构规整性研究相结合，将三种二醚基催化剂的性能与基于邻苯二甲酸酯/硅烷供体对的“传统”MgCl2 负载催化剂以及“无供体”催化剂的性能进行比较。根据获得的实验数据，考虑文献中提出的各种模型，讨论不同供体的作用机制。
Three diethers, 2,2-diisobutyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, and 2-ethyl-2-butyl-1,3-dimethoxypropane, differing in the bulkiness of the alkyl substituents in position 2, have been used as internal donors in MgCl2-TiCl4-diether/AlR(3) catalysts for the polymerization of propylene. The performance of the three diether-based catalysts is compared with that of a ''traditional'' MgCl2-supported catalyst based on the phthalate/silane donor pair and with that of a ''donor-free'' catalyst by coupling the temperature rising elution fractionation (TREF) analysis with a study of the stereoregularity of the first monomeric unit insertion. On the basis of the experimental data obtained, the action mechanisms of the different donors are discussed taking into account the various models presented in the literature.