| abstract |
In a block copolymer (I) containing at least two hard blocks (S1, S2) prepared from a vinylaromatic monomer (M1) and, between them, at least one soft block (BS) prepared from M1 and a diene (M2), the proportion of hard blocks is over 40 wt.% of total (I). Independent claims are also included for the following: (a) mixtures of (I) and additional styrene polymers; and (b) preparation of (I) by sequential anionic polymerization, with at least polymerization of BS being in presence of a potassium salt. |