The present invention includes a composition comprising a coupled impact
propylene copolymer. Preferably, the coupled impact propylene copolymer
has an elastomeric phase that is present in an amount of at least 9 weight
percent of the coupled propylene copolymer. Articles formed from the
coupled propylene copolymer exhibit improved directionally balanced impact
properties as compared with articles formed form comparable noncoupled
impact propylene copolymers and also exhibit improved ductile-to-brittle
transition temperatures compared with comparable noncoupled impact
propylene copolymers. The invention also includes methods for making the
coupled impact propylene copolymers using coupling agents, preferably,
poly(sulfonyl azides). The invention further includes articles of
manufacture that are made from the coupled impact propylene copolymer of
the invention.
