Hetero phase polymer compositions are described. The compositions may have polypropylene component, a modifier component and a compatibilizer component. The modifier component may in some embodiments be an ethylene .alpha.-olefin copolymer with a density .gtoreq.0.905 g/cm.sup.3. In other embodiments the modifier component may be a blend of a copolymer with a density of .gtoreq.0.905 g/cm.sup.3, and an ethylene .alpha.-olefin copolymer of lower, more traditional density.