H NMR and SEC analyses indicate two kinds of active species and corresponding PCL with different structures are existed in the system. Increasing the ratio of glycol to Y(OAr)3 benefits the formation of monofunctional active species.

• 经过1H NMR和SEC分析表明聚合体系中有两种活性中心,形成两种链结构,二醇/Y(OAr)3比值的增大有利于单钇活性中心的形成。