Abstract: Polypropylenes having a reduced tendency to white fracture, which containA) from 70 to 95% by weight of a highly isotactic polypropylene having anisotactic index of more than 90 and a melt flow index between 0.1 and 100 g/10 min, it being possible for the polypropylene to be a homopolymer of propylene or a copolymer of propylene with one or more .alpha.-olefins, having a propylene content of at least 50 mol %, andB) from 5 to 30% by weight of a highly amorphous polypropylene having a crystalline polypropylene fraction of up to 10% by weight with an enthalpy of fusion of not more than 40 J/g and a melt flow index between 0.1 and 100 g/10 min, it being possible for the polypropylene to be a homopolymer of propylene or a copolymer of propylene with one or more .alpha.-olefins, having a propylene content of at least 80 mol %.

Abstract: Process for increasing the proportion of the .beta.-modification in polypropylenes, in which the polypropylenes are melted together with dicarboxylic acid salts of metals of the 2nd main group of the Periodic Table as .beta. nucleating agents and optionally with further conventional additives and are cooled, and polyropylenes which contain dicarboxylic acid salts of metals of the 2nd main group of the Periodic Table as .beta. nucleating agents.

Abstract: Elastomeric polypropylenes modified by grafting and blends thereof with isotactic polypropylenes modified by grafting, and the use thereof as compatibilizers or adhesion promoters for blends and metal composites.