Ziegler-Natta precatalysts were synthetized from Lewis-base-modified-MgCl₂ supports and treated by various Lewis acids, prior to activation by triethylaluminum, in order to increase their activity in ethylene polymerization. BCl₃ provided the highest increase in activity. Interestingly, polymerization results showed no substantial modification of polymer properties, which is consistent with that Lewis acid only promotes the creation of new active sites, after activation by TEA, possessing very similar features to the original ones achievable with conventional precatalysts (i.e. without Lewis-acid treatment).

中文翻译：

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氯化镁的活性增强2酸预处理的负载型齐格勒-纳塔催化剂进行乙烯聚合

由路易斯碱改性的MgCl ₂载体合成齐格勒-纳塔预催化剂，并在由三乙基铝活化之前用各种路易斯酸处理，以增加它们在乙烯聚合中的活性。BCl ₃提供了最高的活性增加。有趣的是，聚合结果表明聚合物的性能没有实质性的改变，这与路易斯酸仅在TEA活化后仅促进新的活性位点的产生相一致，具有与常规预催化剂（即没有路易斯-酸处理）。