Polyolefin based formulations for membranes and fabrics

A multi-layer structure, comprising:

• a layer having a formulation comprising:
• i) an olefin block copolymer comprising an ethylene content of at least 50 mole percent of the whole polymer, the olefin block copolymer having a polydispersity from 1.7 to 3.5, a density of from 0.850 g/cc to 0.925 g/cc, and a melt index from 0.1 g/10 min to 30 g/10 (according to ASTM D-1238 at 190° C./2.16 kg), the olefin block copolymer being an ethylene/octene block copolymer and being present in an amount from 10 wt % to 25 wt % based on the total weight of the formulation;
• ii) a propylene/α-olefin copolymer comprising between 60 and less than 100 weight percent units derived from propylene and between greater than 0 and 40 weight percent units derived from at least one of ethylene and a C4-10 α-olefin, the propylene/α-olefin copolymer having a density greater than 0.855 g/cm3and less than 0.895 g/cm3and melt flow rate from 0.1 to 500 g/10 min (according to ASTM D-1238 at 230° C./2.16 Kg);
• and,
• iii) a halogen-free flame-retardant, a polymer to flame retardant ratio being less than 0.35, and the halogen-free flame retardant being present in an amount of greater than 60 wt % based on total weight of formulation.