在用不同稀土催化剂定向聚合异戊二烯时,发现催化剂的活性有如下顺序:其中Ln(P_(507))_3的活性居于首位,而无水氯化稀土最差。但添加少量乙醇后,我们发现催化活性改变很大,所得结果如图1。 In the case of isoprene polymerization with different rare earth catalysts, the activity of the catalysts was found to be in the following order: Ln (P_ (507)) _3 was the most active one and the anhydrous rare earth chloride was the worst. However, after adding a small amount of ethanol, we found that the catalytic activity changed greatly, and the result is shown in FIG. 1.