Abstract: ABC block copolymers on the basis of butadiene, isoprene and optionally styrene, are provided by a polymerization process wherein the resultant block copolymer comprises:about 40 to 75 wt % of a block A based on butadiene (uniformly distributed vinyl group content less than about 15 wt %),up to about 25 wt % of a block B based on butadiene and isoprene (vinyl content less than about 15 wt %) or based on butadiene (vinyl content more than about 75 wt %)about 20 to 55 wt % of a block C based on butadiene and isoprene (vinyl content more than about 75 wt %). The ABC block copolymers are useful for the production of tire treads.

Abstract: The invention relates to a method for the manufacture of molding materials containing polyphenylene ether (PPE) and to the materials obtained according to this method. Molten PPE containing at least 0.1% volatile components is degasified until it reaches a residual content of volatile components of less than 500 ppm. Subsequently, additional molten polymers and/or additives are added to this molten mass at the lowest possible temperature and both components are mixed.