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研究了新型的改性负载型Ziegler-Natta催化剂,以期制备出组成分布较窄的乙烯-α-烯烃共聚物.通过2,6-iPr2C6H3-OH与TiCl4/ID/MgCl2型负载型钛催化剂在室温下的反应可将芳氧基接到催化剂表面,制得一种改性的烯烃聚合催化剂M-cat.改性催化剂对乙烯聚合及乙烯-1-己烯共聚反应的催化活性与未改性催化剂相近,但共单体效应较弱.前者共聚物的1-己烯含量低于未改性催化剂的产物,但组成分布较窄,分子量较高,且共聚物的沸腾正庚烷可溶级分的序列分布较接近无规分布.三异丁基铝为助催化剂所得聚合活性高于甲基铝氧烷活化的体系.改性催化体系的活性中心分布与未改性体系相比有明显的差别.
A novel modified Ziegler-Natta catalyst was studied in order to prepare ethylene-α-olefin copolymers with narrow compositional distribution.After the 2,6-iPr2C6H3-OH and TiCl4 / ID / MgCl2 supported titanium catalysts were calcined at room temperature Under the reaction can be connected to the aryloxy surface of the catalyst to prepare a modified olefin polymerization catalyst M-cat modified catalyst for ethylene polymerization and ethylene-1-hexene copolymerization reaction activity and unmodified catalyst But the monomer effect is weaker.The former 1-hexene content of the copolymer is lower than that of the unmodified catalyst, but the composition distribution is narrower and the molecular weight is higher, and the boiling n-heptane soluble fraction of the copolymer Is closer to random distribution.The polymerization activity of triisobutylaluminum as cocatalyst is higher than that of methylaluminoxane.The distribution of active sites in modified catalytic system is obviously different from that of unmodified system .