abstract |
Elastomeric block copolymers comprising at least one hard block A composed of styrene monomers and at least one elastomeric block (B/A) composed of styrene monomers and dienes, the glass transition temperature Tg of the block A being more than 25° C. and that of block (B/A) being less than 25° C. and the phase volume ratio of block A to block (B/A) being chosen so that the proportion of the hard phase in the total block copolymer is from 1 to 40% by volume and the amount by weight of the diene is less than 50% by weight, and the relative proportion of 1,2 linkages of the polydiene, based on the sum of 1,2- and 1,4-cis/trans linkages, being below 15%, are prepared by anionic polymerization by means of a lithium alkyl in a nonpolar solvent in the presence of a soluble potassium salt and are used for the production of shaped articles. |