Improved thermoplastic polymer blend compositions comprising an isotactic
polypropylene component and an alpha-olefin and propylene copolymer component,
said copolymer comprising crystallizable alpha-olefin sequences. In a preferred
embodiment, improved thermoplastic polymer blends are provided comprising from
about 35% to about 85% isotactic polypropylene and from about 30% to about 70%
of an ethylene and propylene copolymer, wherein said copolymer comprises isotactically
crystallizable propylene sequences and is predominately propylene. The resultant
blends manifest unexpected compatibility characteristics, increased tensile strength,
and improved process characteristics, e.g., a single melting point.
