以TiCl_4为共引发剂的阳离子聚合体系的络合竞争

Complexation Competition in Cationic Polymerization with TiCl 4 Coinitiator

通过聚合物的ＧＰＣ谱图分析以及紫外光谱测试证明了以ＴｉＣｌ４为共引发剂的阳离子聚合体系中微量水与引发剂和ＴｉＣｌ４之间存在着络合竞争，提出了抑制水对阳离子聚合影响的方法．

The tert butyl acetate/TiCl 4/IB/CH 2Cl 2, Cl 2/TiCl 4/IBVE/C 6H 5CH 3, n butyl propenylate/TiCl 4/IB/ CH 2Cl 2 cationic polymerization systems were studied. Summarizing and comparing results of the GPC traces and the characteristic absorption bands of UV and FTIR spectra respectively, one can conclude: (1) The GPC traces of polymer changed in line with increase of initiator concentration from unimodal with comparatively high w to bimodal showing both high and low w fraction. The former unimodal traces are corresponded to single active center[TiCl 4←H 2O] and the later bimodal traces are corresponded to two active centers comprising both [TiCl 4←initiator] and [TiCl 4←H 2O]. (2) The different properties of polymers obtained by different sequences of chemicals addition and ageing procedure were due to complexation competition and equilibrium which usually required a certain period of time. (3) There are at least two sorts of initiating species in equilibrum.