Fibers made from copolymers of ethylene/α-olefins

A fiber obtainable from or comprising at least one ethylene/α-olefin multi-block interpolymer, wherein the ethylene/α-olefin interpolymer is characterized by one or more of the following properties:

• (a) a Mw/Mn from about 1.7 to about 3.5, at least one melting point, Tm, in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship:
• Tm>−2002.9+4538.5(d)−2422.2(d)2;
• or
• (b) a Mw/Mn from about 1.7 to about 3.5, and a heat of fusion, ΔH in J/g, and a delta quantity, ΔT, in degrees Celsius defined as the temperature difference between the tallest DSC peak and the tallest CRYSTAF peak, wherein the numerical values of ΔT and ΔH have the following relationships:
• ΔT>−0.1299(ΔH)+62.81 for ΔH greater than zero and up to 130 J/g,
• ΔT≧48° C. for ΔH greater than 130 J/g,
• wherein the CRYSTAF peak is determined using at least 5 percent of the polymer, and if less than 5 percent of the polymer has an identifiable CRYSTAF peak, then the CRYSTAF temperature is 30° C.;
• or
• (c) an elastic recovery, Re, in percent at 300 percent strain and 1 cycle measured with a compression-molded film of the ethylene/α-olefin interpolymer, and a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when the ethylene/α-olefin interpolymer is substantially free of a cross-linked phase:
• Re>1481−1629(d);
• or
• (d) a molecular fraction which elutes between 40° C. and 130° C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer comprises the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α-olefin interpolymer, wherein the fiber is not cross-linked.