Synthesis of block-graft polymers by anionic polymerizations

Two poly(3-methylstyrene) (P4MS)-block-polystyrene (PS)-block-P4MS triblock copolymers were prepared by successive anionic addition of styrene and 4-m ethylstyrene monomers as the core backbone (CB) for the architecture of blo ck-graft polymers. Both terminal 4-methylstyrene blocks of CB were metalate d with a sec-butyllithium (sec-BuLi)/tetramethylethylene-diamine (TMEDA) co mplex in cyclohexane. The first-generation block-graft polymer (1BG) was pr epared by anionic polymerization of alpha-methylstyrene by the lithiated CB in tetrahydrofuran (THF) at -78 degrees C and subsequently the terminal gr aft ends were capped with a small amount of 4-methylstyrene. The characteri zation of those block-graft polymers was carried out in detail.