Cl_2/TiCl_4体系引发IBVE活性阳离子聚合的研究(Ⅰ)——引发活性中心及其络合竞争

Cationic Polymerization of IBVE Initiated by Cl_2 TiCl_4/Toluene ( Ⅰ )--Initiating Centers and the Role of Their Complex Competition in the Polymerization

采用UV光谱法证明了IBVE/Cl_2/TiCl_1/甲苯聚合体系中同时存在着两种引发活性中心及络合竞争,研究了Cl_2/TiCl_1和H_2O/TiCl_1络合平衡,求出了20℃时2TiCl_1←Cl_2和TiCl_1←H_2O络合平衡不稳定常数.

There coexist at least two initiating centers. The monomodal trace of the polymer in GPC was observed when only one active center outlives after complexing competition. In the given system IBVE/Cl2/TiCl4/toluene the complexing competition is between Cl2/TiCl4 and H2O/ TiCl4 where in the trace of water existed as residual impurity being not thoroughly removed by usual purification technique. The unstable equilibrium constants for complexation reaction of Cl2/TiCl4 and H2O/TiCl4 were determined for them as 1. 9×10-10 and 8. 31×10-6 respectively. The huge difference between their unstable equilibrium constants shows active complex Cl2/TiCl4 is predominate, then “living” characterastic of the polymerization is outstanding.