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以TiCl_4-Al(i-Bu)_3为催化剂室温下进行Ⅰ-十六烯聚合。当Al/Ti比小于1.75时得到了分子量低于5000、每条聚合物链带—个反式内双键的低聚物,而Al/Ti比升高时产物逐渐变为高分子量聚合物。实验表明该催化体系中存在分别产生低聚物和高聚物的两类活性中心。这种产生低聚物的活性中心不同于一般Lewis酸引发的阳离子聚合中心,推测是一种按二级插入机理增长、很易发生β-氢迁移的特殊的配位聚合活性中心。
I-hexadecene polymerization was carried out at room temperature using TiCl 4 -Al (i-Bu) _3 as catalyst. When the Al / Ti ratio is less than 1.75, oligomers having a molecular weight of less than 5000 per double chain of a polymer chain are obtained, and the product becomes a high-molecular-weight polymer as the Al / Ti ratio increases. Experiments show that there are two types of active sites in the catalytic system that produce oligomers and polymers, respectively. This oligomer-producing active center is different from the general Lewis acid-initiated cationic polymerization center and is presumed to be a special coordination polymerization active site which is prone to β-hydrogen migration by secondary insertion mechanism.