Synthesis of Nitroxide-Functionalized Polybutadiene Using Halogen-Containing Benzyloxyamine as Terminators for Anionic Polymerization

Synthesis of benzyloxyamine end-functionalized polybutadiene was investigated using halogen-containing benzyloxyamines as terminators for anionic polymerization of butadiene (BD). The two terminators studied were 2,2,6,6-tetramethyl-1-(2-bromo-1-phenylethoxy)piperidine ( 1 ), synthesized by allowing styrene to react with 1-oxo-2,2,6,6-tetramethylpiperidinium bromide, and 2,2,6,6-tetramethyl-1-(2-cumyloxy-1-(chloromethylphenyl)ethoxy)piperidine ( 2 ), synthesized by allowing chloromethylstyrene to react with dicumyl peroxide in the presence of TEMPO. Termination studies of poly(butadienyl)lithiums using 1 and 2 were carried out in heptane/tetrahydrofuran mixtures. Nearly quantitative yields of benzyloxyamine end-functionalized polybutadienes were obtained when the termination reactions were carried out at −78 °C. However, yields were much lower when terminations were carried out at ambient temperature.