Model kinetic study of TiCl4-induced ionization of polyisobutene capped with diphenylethylene application to the synthesis of block copolymers

The use of non-homopolymerizable monomers such as 1,1-diphenylethylene (DPE) in the synthesis of functional polymers and block copolymers by cationic polymerization has been recently reported. The most important parameters in this process, the kinetics and extent of ionization and capping as well as the stability of the cation, were investigated by studying the reaction with TiCl4 of 1-methoxy-1,1-diphenyl-3,3,5,5-tetramethylhexane, a model for DPE-capped polyisobutene chain-end. This study was performed using H-1 NMR and the high-purity stopped-flow device coupled with W-visible spectroscopy.