Selectively permeable protective structure and articles therefrom

An article comprising a selectively permeable structure wherein the structure comprises a composition comprising (a), (b), and optionally (c);

• (a) is a combination comprising (i) and (ii), wherein (i) is one or more ethylene acid copolymers;
• and (ii) is one or more organic acids;
• wherein at least 50% of the combined acidic groups in the acid copolymer and the organic acid are nominally neutralized to salts with metal ions and at least 50% of the metal ions are alkali metal ions;
• (b) is a terpolymer of ethylene, acrylic acid or methacrylic acid, and an alkyl acrylate or alkyl methacrylate;
• and
• (c) is one or more ethylene-containing polymers selected from the group consisting of polyethylene homopolymers, copolymers of ethylene and an α-olefin, copolymers of ethylene and a diolefin, and ethylene copolymers obtained from copolymerization of ethylene with at least one polar monomer selected from the group consisting of vinyl acetate, acrylic ester, methacrylic ester and carbon monoxide, wherein the ethylene-containing polymer does not comprise a carboxylic acid comonomer.