TiCl_3-AlR_3-1-辛烯体系ESR跟踪研究

ESR Study of TiCl_3-AlR_3-1-Octene System

用ESR方法对TiCl_3、TiCl_3-AlR_3体系及TiCl_3-AlR_3-1-辛烯体系进行了跟踪研究,并研究了预聚对ESR信号的影响。发现络合Ⅱ型TiCl_3-AlR_3-1-辛烯体系存在三种顺磁中心,且三种顺磁中心都是聚合活性中心。预聚并不改变该体系活性中心的种类和结构。还发现Stauffer AA TiCl_3-AlE_3-1-辛烯体系中多种活性中心并存的现象与络合Ⅱ型TiCl_3-AlEt_3-1-辛烯体系无本质区别。

The ESR spectroscopy of TiCl_3, TiCl_3-AlR_3 and TiCl_3-AlR_3-1-octene system was studied. It was discovered that there existed three kinds of paramagnetic centers which corresponded to three kinds of polymerization active centers in the system of TiCl_3-AlEt_3-1-octene. The phenomenon of different polymerization active centers coexisting in the system of Stauffer AA TiCl_3-AlEt_3-1-octene was similar to that of complex Ⅱ TiCl_3-AlEt_3-1-octene system. It was also testified that the kinds and structure of the polymerization active centers of TiCl_3-AlEt_3-1-octene system were not affected by the prepolymerization of 1-octene, ESR proves to be a direct way to elucidate the phenomenon of different active centers coexisting in the system of heterogeneous Ziegler-Natta catalysts.