Abstract: Fibers that exhibit good elasticity or extensibility and tenacity, and low modulus are prepared from propylene-based copolymers. The propylene-based copolymers comprise at least about 50 weight percent (wt %) of units derived from propylene and at least about 8 wt % of units derived from one or more comonomers other than propylene, e.g., ethylene. Particularly preferred propylene copolymers are characterized as having 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. In one aspect of the invention, fibers are subjected to stress-induced crystallization by subjecting the fiber to tensile elongation during draw.

Abstract: Fibers comprising a propylene homopolymer or a copolymer of propylene and at least one of ethylene and one or more unsaturated comonomers exhibit desirable properties. The homopolymers are characterized as having 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. The copolymers are characterized as (A) comprising at least about 60 weight percent (wt %) of units derived from propylene, and (B) having at least 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, S1x, greater than about −1.