Unique copolymers comprising propylene, ethylene and/or one or more unsaturated
comonomers are characterized as having: at least one, preferably more than one,
of the following properties: (i) 13C NMR peaks corresponding to a regio-error
at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value
greater than about 1.4 when the comonomer content of the copolymer is at least
about 3 wt %, (iii) a skewness index, Six, greater than about -1.20,
(iv) a DSC curve with a Tme that remains essentially the same and a
Tmax that decreases as the amount of comonomer in the copolymer is increased,
and (v) an X-ray diffraction pattern that reports more gamma-form crystals than
a comparable copolymer prepared with a Ziegler-Natta catalyst. These polypropylene
polymers are made using a nonmetallocene, metal-centered, heteroaryl ligand catalyst.
These polymers can be blended with other polymers, and are useful in the manufacture
of films, sheets, foams, fibers and molded articles.