Control of molecular weight distribution for polyethylene catalyzed over Ziegler–Natta/Metallocene hybrid and mixed catalysts
Control of molecular weight distribution for polyethylene catalyzed over Ziegler–Natta/Metallocene hybrid and mixed catalysts
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DOI：
10.1016/s1381-1169(00)00222-3
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发表时间：
2000-10
影响因子：
--
通讯作者：
H. Cho;J. Chung;W. Lee
中科院分区：
文献类型：
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作者：
H. Cho;J. Chung;W. Lee
分别采用重结晶法和溶胶-凝胶法制备了MgCl 2和SiO2两种用于浸渍催化剂的无机载体。为了控制乙烯聚合过程中的分子量（Mw）和分子量分布（MWD），制备了Ziegler-Natta/茂金属杂化和混合催化剂。由齐格勒-纳塔/茂金属杂化和混合催化剂生产的聚乙烯显示出两个熔融温度和双峰MWD，对应于由每种单独催化剂产生的产物。这表明这些齐格勒-纳塔/茂金属催化剂充当单独的活性物质并产生聚合物的共混物。
Two types of inorganic supports, MgCl2and SiO2, for use in the impregnation of catalysts, were prepared by the recrystallization and the sol–gel methods, respectively. The Ziegler–Natta/Metallocene hybrid and mixed catalysts were prepared in order to control the molecular weight (Mw) and the molecular weight distribution (MWD) during ethylene polymerization. The polyethylene produced by the Ziegler–Natta/Metallocene hybrid and mixed catalysts showed two melting temperatures and a bimodal MWD, corresponding to products arising from each of the individual catalysts. This suggests that these Ziegler–Natta/Metallocene catalysts acted as individual active species and produced a blend of polymers.