Isocyanate-reactive compositions, polyurethane foams formed therefrom, multi-layer composite articles that include such foams, and methods for their preparation

A polyurethane foam-forming reaction mixture comprising:

• (a) a polyisocyanate present in an amount sufficient to provide an isocyanate index of 0.6 to 1.3;
• (b) a polyol blend comprising:
• (i) a polyether polyol having a functionality of 2 to 6 and an OH number of 20 to 50 mg KOH/g, which is present in an amount of at least 10% by weight, based on total weight of polyol in the polyurethane foam-forming reaction mixture and which is a reaction product of an alkylene oxide and a di- or higher functional renewable polyol starter;
• and
• (ii) an aromatic polyester polyol having a functionality of 1.5 to 3 and an OH number of 150 to 450 mg KOH/g, which is present in an amount of at least 15% by weight, based on total weight of polyol in the polyurethane foam-forming reaction mixture;
• (c) a blowing agent composition comprising water, the water being present in an amount of 0.5 to 10% by weight, based on total weight of the foam-forming reaction mixture and in an amount of at least 90% by weight, based on total weight of the blowing agent composition;
• and
• (d) a catalyst,
• wherein the polyurethane foam-forming reaction mixture has a green content of at least 15% by weight, based on total weight of the polyurethane foam-forming reaction mixture.