Synthesis of nitroxide-functionalized polybutadiene using halogen-containing benzyloxyamine as terminators for anionic polymerization

Synthesis of benzyloxyamine end-functionalized polybutadiene was investigat ed using halogen-containing benzyloxyamines as terminators for anionic poly merization of butadiene (BD). The two terminators studied were 2,2,6,6-tetr amethyl-1-(2-bromo-1-phenylethoxy)piperidine (1), synthesized by allowing s tyrene to react with 1-oxo-2,2,6,6-tetramethylpiperidinium bromide, and 2,2 ,6,6-tetramethyl-1-(2-cumyloxy-1-(chloromethylphenyl)ethoxy), synthesized b y allowing chloromethylstyrene to react with dicumyl peroxide in the presen ce of TEMPO. Termination studies of poly(butadienyl)lithiums using 1 and 2 were carried out in heptane/tetrahydrofuran mixtures. Nearly quantitative y ields of benzyloxyamine end-functionalized polybutadienes were obtained whe n the termination reactions were carried out at -78 degrees C. However, yie lds were much lower when terminations were carried out at ambient temperatu re.