反应详情

The procedure described in Example 1 was utilized in this example except that 3 mL of 1 M solution of n-butyl lithium (n-BuLi) in hexanes and 5 mL of 1 M solution of TMEDA in hexanes were added to the catalyst system (BaTHFA/MgR2) making the molar ratio (BaTHFA/MgR2/n-BuLi/TMEDA) 1:3:3:5. The styrene-butadiene produced was determined to have a glass transition temperature (Tg) at −76° C. and a melting temperature (Tm) at −11° C. The Mooney viscosity (ML-4) at 100° C. was 48. The GPC measurements indicated that the polymer has a number average molecular weight (Mn) of 175,000 g/mol and a weight average molecular weight (Mw) of 270,000 g/mol. The polydispersity (Mw/Mn) of the resulting polymer was 1.54. Carbon-13 NMR analysis showed a trans 1,4 polybutadiene content of 75%, cis 1,4 polybutadiene content of 19%, a 1,2 polybutadiene content of 6%, and a polystyrene content of 16.5%.

1. additionwere added to the catalyst system (BaTHFA/MgR2)